jdm b16a is the nsx one, and the usdm one is just whatever the dealership gives you. i've had to change one of each lol. you can realistically make either work for either application i think. one is just a liiiitttle bit larger than the other and one has rounded vs kinda squared edges. i know after doing some research on honda-tech i found the actual honda part # for each application though, do some more research if you're not 100% confident.