The belts are manufactured for Nissan by Bando, and their part numbers are stamped on the belt, so I took a chance on Bando aftermarket belts. I assume that since their part number is stamped on the factory belts, they're the same thing. The belts arrived in about 3 days from Rock Auto for $16.87 shipped for both belts. I also bought a KriKit 2 belt tension gauge from NAPA (p/n NBH KR2 ). These are a little cheaper on Amazon, but I didn't want to wait for it to arrive. If you're not familiar with the KriKit, check it out here. https://www.youtube.com/watch?v=z11wfc-0-hY
I have always used the "twist method" for tensioning belts, with varying degrees of success. I think I have traditionally under-tensioned belts after playing with this tension gauge. This tool worked very nicely, especially because the test points on the top of the belts are very accessible when you remove the air duct. It surprised me how much one or two turns of the tensioner bolt impacts the tension on the belt once you're close to the spec.
My wife reports that the car was "squeal free" this morning, and she was able to leave the a/c compressor on driving out of the neighborhood, so
