HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Discuss the RB20, RB25 and RB26 series engines.
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HIGHFIV5
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HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby HIGHFIV5 » Sat May 01, 2010 12:33 pm

During my swap i decided to make a wiring guide that even the biggest noobs shouldnt have a hard
time following. I looked at all the various guides out there and added what they were missing and
clarified the bits that may confuse others. During my wiring i traced every wire back to the
ECU pinout and verified its location and use. The result...started up first try without any troubles! :)
I hope this guide can help anyone figure out the wiring for their S13 and save them a couple hundred
bucks so they can dump that into their car or motor. The wiring isnt something anyone should be afraid of...
Im 18, this is my first swap and my first attempt at the wiring and i had no problems.
I reccommend starting with the cleanest most unmolested harness you can. This will make
things a million times easier. Also, dont use butt connectors....i used metal crimps
that you also solder afterwards for all my connections. And shrink wrap people not
electrical tape. Finish it all off with some fresh loom and your good to go!
Anyways onto the guide! Note that this is SOHC---RB20 so their might be some difference
in DOHC but this should set yeh on the right path regardless. Also, with it being SOHC,
my tach did not work...need a DOHC, or tach config, or aftermarket or R32 tach.

I will include pics of the plugs and such so again there is no confusion as to what plug is
being mentioned.

These are all the wires functions in the various plugs.

S13 BROWN PLUG

SOLID/STRIPE

BLACK/PINK------------- FUEL PUMP
GREEN/ORANGE------- NEUTRAL SWITCH
BLACK/YELLOW------- IACV POWER
RED/ BLACK------------- ECU RELAY
BROWN------------------- 02 SENSOR
BROWN------------------- 02 SENSOR
PINK----------------------- N/A
YELLOW/GREEN------ N/A

S13 GREY OVAL PLUG

BLACK/RED(THICK)----------- MAIN IGNITION POWER
RED (MEDIUM)------------------ ECU BACKUP/CONSTANT POWER
BLACK/WHITE(MEDIUM)---- ECU POWER
BLUE/GREEN-------------------- AC RELAY
GREEN/YELLOW--------------- AC RELAY
BLACK---------------------------- GROUND
RED/BLUE----------------------- N/A

These are the brown and grey S13 plugs you need to use. They plug into the main fuse box on
the passenger side. Note the tape...i recommend marking all the wires that you will be using before doing
any wiring. Makes things very easy to navigate and the whole wiring process quicker in the end.

Image

S13 DASH PLUG

YELLOW/RED------------------- TACH SIGNAL
YELLOW/GREEN--------------- SPEED SIGNAL
ORANGE-------------------------- IGNITION START
BLUE/BLACK-------------------- WATER TEMP SENSOR
BLUE/GREEN-------------------- AC SIGNAL
RED--------------------------------- CHECK ENGINE LIGHT
BLACK---------------------------- GROUND

This one shouldnt be hard to find at all...but here's a pic anyways.
Image

RB20 SQUARE 6 WIRE PLUG

WHITE PURPLE(THICK)----------- IGNITION RELAY
RED/BLACK (THICK)-------------- MAIN IGNITION POWER
WHITE/BLACK (MEDUIM)------- ECU MEMORY
GREEN/ORANGE------------------- NEUTRAL SWITCH
TEAL----------------------------------- N/A
LIGHT BLUE------------------------- N/A

This is the RB20 6-Wire plug. Its a big ugly grey rectangular plug.
Image

RB20 DASH PLUG

BLACK/PINK-------------------- FUEL PUMP
YELLOW/RED------------------ TACH SIGNAL
YELLOW/GREEN-------------- VEHICLE SPEED SENSOR
BLACK/YELLOW-------------- IGNITION START SIGNAL
ORANGE/BLACK-------------- CHECK ENGINE LIGHT
TEAL----------------------------- AC RELAY
TEAL/RED---------------------- AC SWITCH
*NOTE*------ FSM states PIN #32/Check engine light as PINK/BLACK
But mine was ORANGE/BLACK



I’m going to include the wire-wire as well as the plug-plug locations to sort out any confusion that could be had during the wiring process.


S13 WIRE/RB20 WIRE
SOLID/STRIPE

DASH PLUG WIRING

YELLOW/RED------------------- TACH SIGNAL------------------ YELLOW/RED
YELLOW/GREEN--------------- SPEED SIGNAL----------------- YELLOW/GREEN
ORANGE-------------------------- IGNITION START-------------- BLACK/YELLOW
*NOTE* The BLACK/YELLOW wire should trace back to PIN #43, which you might have read about on the other guides.
BLACK/PINK---------------------FUEL PUMP---------------------- BLACK/PINK
S13 wire found on the BROWN plug. RB20 wire found on the DASH PLUG.
I actually extended the wire from the dash plug to the brown to make sure it would reach
and plug in.
RED------------------------------ CHECK ENGINE LIGHT-------------- ORANGE/BLACK
BLACK---------------------------- GROUND

Fuel pump wire on the RB dash plug.
Image



RB20 SQUARE 6 WIRE PLUG--- GREY & BROWN S13 PLUGS

S13 WIRE/ RB20 WIRE


GREEN/ORANGE------- -----NEUTRAL SWITCH-------------- GREEN/ORANGE
[BROWN PLUG]
RED (MEDIUM)---------- ECU BACKUP/CONSTANT POWER------WHITE/BLACK
[GREY OVAL PLUG]
BLACK/RED(THICK)-------- MAIN IGNITION POWER------BLACK/RED(THICK)
[GREY OVAL PLUG]
WHITE(THICK)-------- -----IGNITION RELAY------------ WHITE/PURPLE (THICK)
[LOCATED IN FUSE BOX. WILL LIKELY HAVE TO PEEL BACK THE LOOM. THERE WILL BE 2 WHITE WIRES. ONES REALLY THICK AND THE OTHERS NORMAL THICK. YOU OBVIOUSLY WANT THE NORMAL THICK ONE.
This is the last wire you should worry about. Dont wire this one till the harness is all routed through the
firewall and such.]

Here's the ignition switch wire in the fuse box wiring. You gotta cut it and strip both sides.
Image

I tied the WHITE/PURPLE RB wire into the one side of the WHITE S13 wire then
crimped them together then crimped the other half of the WHITE wire into them then soldered
and shrink wrapped.

Image

NOTE: Be sure to extend the MAF and O2 sensor plugs before doing this last step as
it will be much easier outside the car. O2 needs approximately 3 feet and MAF needs about another 4 feet.
Be sure to use shielded wire.


Here is the finished product! That wasn't so bad now was it? ;)
Image

Image

As far as the lower harness goes....just use the KA lower harness. Pretty much everything plugs in with the exception
of the oil pressure sensor in which case you can splice the RB plug on or just use the KA oil pressure sensor
or go aftermarket. Also, i stripped AC from my car so did not include AC wiring in this guide but did include
the wires that are for AC.

Last but not least. I found these two resources to be some of the most useful. I verified every wire
back to the ECU and recommend you do the same. Not every harness is the same so check to be sure.
These lase two pics though i cannot take credit for. The first was made by a fellow NICO member
and was found on one of the threads here. I verified every wire with the FSM.


Image

And use this to find the pin location.
Image


Hope this guide serves as a valuable resource to everyone and helps you get on the road with your RB20!

This guide was made by Adrien Lengyel (HIGHFIV5). Don’t take credit for others work….
Follow this wiring guide at your own discretion. I am not responsible for any failures that may come from this guide.
Last edited by HIGHFIV5 on Sat Nov 24, 2012 1:03 am, edited 1 time in total.


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Lonismos14
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby Lonismos14 » Sat May 01, 2010 1:35 pm

Hey do you have the stock maf and if you do whats the serial number? Is it j60

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RustspecS13
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby RustspecS13 » Sun May 02, 2010 4:50 pm

I did not need to extend my maf wiring with my stock RB20, and I don't think you have too unless you want to route the wiring as far away as possible from the turbo.

I just de loomed the o2/maf wiring all the way back to the main harness and it gave me the slack to run them where I needed them no splicing. The o2 went right where it needed too with no problem, and the maf is ran under the throttle body intake piping, but i also made a bracket to the 10mm bolt that goes into said piping. Then I zip tied the maf wires to that, and I didn't have any problems.

I just wanted to keep it oem as possible with the maf so that the signal stayed as clean as possible.

~Alex

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HIGHFIV5
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby HIGHFIV5 » Sun May 02, 2010 9:29 pm

Definitely a good way to do it but not everyone wants to deloom it all that way.
Yeh definitely dont have much extra the way they loom it up from factory!
If yeh do a good job itll turn out quite nice. mine turned out good.
Good addition though to the guide for others to consider, cause
really extending the MAF sucked....2 little wires inside a shielded brown wire
wrapped with the thin metal shielding...its retarded and a pain in the a** haha.

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Kansei240sx
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby Kansei240sx » Mon May 03, 2010 3:50 pm

Oh dude, this is so freaking awesome man.

I havent done an RB20 harness in about a year and a half and i've been scowering the internet looking for a great write up for one of my customers S13 RB20 harness conversions.

You rock man!! I'll post any feed back i can, i do RB25 and SR20 harness conversions weekly almost , so having this helps out!

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HIGHFIV5
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby HIGHFIV5 » Mon May 03, 2010 3:53 pm

Thanks man glad i could help!
Yeh a good, easy to understand guide is not too
easy to find these days!

DeclareYrWar

Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby DeclareYrWar » Mon May 10, 2010 3:29 pm

What did you do for your o2 sensor power wire that is located on the rb20 dash plug? It's brown. I'm assuming you wired it to the brown wire on the brown s13 chasis plug?

Edit: Nvm, wired it up myself to a 12v ignition source. I was hoping you could elaborate on the way you wired the ignition switch. Did you hardwire this connection so that your harness can no longer be removed from the car if need be or did you wire the purple/white wire into a plug. Just curious as to how you did it and what made you choose to do it that way.

xnyc1
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby xnyc1 » Thu May 13, 2010 5:06 pm

you should try to get this stickied or put into the tech section as this is one of the more detailed writeups. everything seems right though from how my wiring went

edit//
if your running the rb into a s13 you dont use the rb wiper harness at all (it is the middle connector with the yellow endcap in the 4th pic, in-cabin connector). you can run wires/sensors/switches/etc to the rb wiper motor connector and continue back in-cabin without having a mess of exposed wiring.

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HIGHFIV5
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby HIGHFIV5 » Thu May 13, 2010 7:36 pm

DeclareYrWar wrote:What did you do for your o2 sensor power wire that is located on the rb20 dash plug? It's brown. I'm assuming you wired it to the brown wire on the brown s13 chasis plug?

Edit: Nvm, wired it up myself to a 12v ignition source. I was hoping you could elaborate on the way you wired the ignition switch. Did you hardwire this connection so that your harness can no longer be removed from the car if need be or did you wire the purple/white wire into a plug. Just curious as to how you did it and what made you choose to do it that way.
Yes it is hardwired into the ignition wire as you can see in the two pictures provided there.
Chose to do it that way cause really...its the easiest way haha.
xnyc1 wrote:you should try to get this stickied or put into the tech section as this is one of the more detailed writeups. everything seems right though from how my wiring went

edit//
if your running the rb into a s13 you dont use the rb wiper harness at all (it is the middle connector with the yellow endcap in the 4th pic, in-cabin connector). you can run wires/sensors/switches/etc to the rb wiper motor connector and continue back in-cabin without having a mess of exposed wiring.

Who would i talk to bout getting this stickied? Azhitman??
And ooooh jeeze is that what that plugs for? Awesome man thanks that could definitely
come in handy!

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kozanatos
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby kozanatos » Tue Jun 01, 2010 10:40 am

A lot of time and effort.
Got a guide, and you verified somebodies wiring table too, Appreciate it!
This will definitely help a lot of people.
If you feel like adding anything, maybe show how you routed the wires or something :confused:
You never know if somebody will run them across the engine bay ;)

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HIGHFIV5
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby HIGHFIV5 » Fri Jul 09, 2010 6:17 pm

BUMP! Why isnt this stickied yet?!?!
AZ said he would sticky and add it to the articles a long time ago!
Come on mods people need to see this,
would stop a whole helluva lot of RB20 wiring threads.

EDIT: Thanks mods!!! Now this threads where it belongs, right on the front page where everyone can see it
rather than buried in the RB forums somewhere. :dblthumb:

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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby bmadd2402 » Mon Apr 18, 2011 4:51 pm

Are there any wiring differences between the 89-90 to the 91-94?

dassit
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby dassit » Wed Nov 09, 2011 6:33 pm

:confused: good question ^^

dassit
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby dassit » Wed Nov 09, 2011 6:40 pm

for my rb20 i only 4 WIRES for the SQUARE 6 WIRE PLUG

and the 4 wires are:
WHITE PURPLE(THICK)———– IGNITION RELAY
RED/BLACK (THICK)————– MAIN IGNITION POWER
WHITE/BLACK (MEDUIM)——- ECU MEMORY
LIGHT BLUE————————- N/A

I dont have:
GREEN/ORANGE——————- NEUTRAL SWITCH
TEAL———————————– N/A

mikewtimm
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby mikewtimm » Mon Dec 05, 2011 3:53 pm

this is my first time and i need help with the S13 gray oval plug (labeling) the one im holding right now does not seem to match your colors exactly and i know its the right plug. my colors are
black/pink(thick)
red(medium)
black/white(medium)
green/yellow
blue/green
orange/blue
yellow/green
blue
i need help with the bottom 3!

Faust01
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby Faust01 » Sat Jan 07, 2012 5:04 pm

Random question but why'd you do a rb20e instead of doing the rb20de ??



Can you guys help me. Ive just done the de swap. I Only have the rb harness not the CA

I need to plug my Alternator positive lead somewhere as its loose, where's the right place to plug it ?

Where are the wires in the engine bay that I need to hook my speed sensor too ?

Tacho wires under the dash.. I hooked the ecu wire up to a test light while running,, wire seems dead.

Temp Gauge.. which under dash wires do I link ?

Battery light - doesnt show, ever. Is it because alternator isnt hooked up ?

cheers

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HIGHFIV5
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby HIGHFIV5 » Sun Jan 15, 2012 8:15 pm

bmadd2402 wrote:Are there any wiring differences between the 89-90 to the 91-94?
There is slight differences in wiring but they are minimal.
Alot of the info i gathered and have shown in this guide was gathered from
DOHC--> RB20 swap guides and checked according to the SOHC wire diagrams.
Most of it crosses over but not everything matches up, cross reference
my guide with others as most guides are DOHC (91-94) swaps where mine was the SOHC (89-90)
Make sure you double check and verify every wire using the factory ecu pinouts
for your application, never rely on matching wire colors.


Faust01 wrote:Random question but why'd you do a rb20e instead of doing the rb20de ??



Can you guys help me. Ive just done the de swap. I Only have the rb harness not the CA

I need to plug my Alternator positive lead somewhere as its loose, where's the right place to plug it ?

Where are the wires in the engine bay that I need to hook my speed sensor too ?

Tacho wires under the dash.. I hooked the ecu wire up to a test light while running,, wire seems dead.

Temp Gauge.. which under dash wires do I link ?

Battery light - doesnt show, ever. Is it because alternator isnt hooked up ?

cheers

Umm this is the RB20DET, SOHC refers to the KA24E that was in it before the swap.
You only have the RB20 harness?? Are you doing CA18 to RB20 swap or was that a typo? Or KA24E/DE??
If your doing CA18 to RB swap this guide will only help you as far as identifying the
RB20 side of things but will not help you as for the CA side of the harness which youd need.
You need to do alot more research i can see...i wouldnt suggest trying to do this unless
you have done you're research and been thorough about it.
Ill be nice and spoon feed you what i can but start using the search button more often because
this info is out there.
1. Alternator positive lead---- uhhh self explanatory...goes to the positive lead of your battery.
2. Speed sensor is on your tranny. RB20 uses cable driven speed sensor. assuming your doing your swap in an S13
the KA tranny speed sensor will plug right in and is an electronic one that you will have to splice into your harness.
3. Tach wires- are noted in my guide and others.
4. Temp gauge- dont bother just go aftermarket its easier to wire and way more accurate.
5. Battery light- most likely due to the fact your alternator is not hooked up.

Search harder, the answers to all your questions are out there. Dont rush through the wiring
until youve done alot of research as everyones wiring experience is gonna be slightly different.

nskyle
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby nskyle » Mon Mar 19, 2012 2:01 pm

Could someone help me out. Im looking to purchase a apexi safc. Im kinda lost on witch wires i would slice into on my ECU the car is a s13 with a RB20det swap thanks.

LeD ippen
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby LeD ippen » Wed Jun 20, 2012 8:53 pm

the ecu pinout is wrongs picture

this is right one Image

almost gave ground to a power source :X for my a/c

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HIGHFIV5
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby HIGHFIV5 » Sat Nov 24, 2012 1:06 am

LeD ippen wrote:the ecu pinout is wrongs picture
Thank you! Fixxed!

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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby s13fever » Sun Sep 21, 2014 12:37 pm

where does the IACV from the s13 chassis plugs go to? I just need help asap. thanks.

angusyoung
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby angusyoung » Tue Dec 30, 2014 11:53 am

hi this may be a silly question but will this guide work on a vg30dett as im trying to wire into a z31 any help pleasssssse nige

skyline8075
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby skyline8075 » Fri Oct 02, 2015 8:30 am

ANYONE WITH A 240SX HELP WIRING!!! The first picture in this post of the brown plug and the gray plug. Someone long time ago cut the plugs off my car I'm working on repairing it. Can anyone with a 240sx give me a pinout of the exact color of wire and location on the plug it is. Here or at skyline8075 @ yahoo dot com

I have all the wires I just need to know where on the plug they go thanks.

Audel650
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby Audel650 » Fri Mar 25, 2016 5:11 pm

Can someone really help me with the wiring i have a couple question I have the tranny and engine in the car already !Please and thank you!

joel240s13
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby joel240s13 » Thu Jan 11, 2018 6:14 pm

Hi there just a question regarding the s13 or rb20 dash plugs.

Are the dash plugs in the car harness or on the engine harness. Because im doing the swap but its a RB25 and the RB25 loom has other plugs for the dash i think so if so is there anyone that knows how to wire the RB25 harness to s13. Also its a series 1 harness.

Apart from that huge help mate especially with the photos.

Dev894
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1990 Nissan 240SX RB20

Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby Dev894 » Wed Mar 07, 2018 11:19 am

great right up, just curioue, both white wires go to the battery terminal on my car, can i just make a lead from the purple/white rb wire up to my battery?

RandyBonnette
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Re: HIGHFIV5's RB20---> S13 Wiring Guide For Dummies

Postby RandyBonnette » Wed Jun 05, 2019 1:29 am

cheap essay
Hi there just a question regarding the s13 or rb20 dash plugs.

Are the dash plugs in the car harness or on the engine harness. Because im doing the swap but its a RB25 and the RB25 loom has other plugs for the dash i think so if so is there anyone that knows how to wire the RB25 harness to s13. Also its a series 1 harness.

Apart from that huge help mate especially with the photos.
Hello,

I used a harness which was particularly engineered for a USDM S13 240sx. And it comes with the RB25DET engine swap. You can also check WiringSpecialities products.


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