So someone mentioned that some AR-5RM have a sticker that you see after removing the battery. They mention M and L, but on my batch of AR-5RM, the sticker is FK. So these are fully unlocked. For me, the model that worked in CHIRP was UV-5RH. Also, I was able to use Odmaster software with the Bluetooth dongle. Funny, but after I programmed the radio with Odmaster, then CHIRP recognized it a 5RM. As always YMMV.