need help reinstalling factory radio

[krytical56]

i just bought a used 2009 altima 2.5s sedan non bose system without a radio.
i bought a factory radio off ebay and am gonna install it myself.
the problem is the previous owner had already cut the stock wire harnesses except for the atenna
and i know theres 4 plug ins behing the radio, ones for the atenna one is for this one...
http://www.ebay.com/itm/OEM-Reverse-Mal ... 35&vxp=mtr
but i have no idea whats the other 2 are for and which wire harness i need for them
can someone help me out, thanks in advance