I got one of the earlier RSA triggers from Midway awhile back. It apparently was one of the earlier models and required quite a bit of fitting to go into my SAR1. It was NOT a "drop in" thing. A good couple of hours and a lot of filing, sweating, and cussing later it was in and now that it is, its a great trigger. I didnt even need to fiddle with the adjustments as it was fine as it came in that department. I talked to one of the boys at Red Star later on and was told they were a group of older triggers and that the newer ones had taken care of some of the problems I had had(of course!). He said with so many different models of AK and different tolerances with each country, it was tough, but they were getting there. If you are getting the older triggers, you will need a set of jewelers files and be willing to do some metal removal to get them in. Your best bet if your going to get one is to order directly from them, that way you get, or at least can ask for, the latest model.