Bought for several builds, never had an issue - Luth-AR A1 Rear Sight Assembly

Honestly, it's exactly what it is. An A1 rear sight. It's a pain to install, pain to adjust, etc. Before you start your build make sure you use copious amounts of gun oil on the upper, this will help you greatly with the install. To be clear, this isn't the fault of the parts. The parts are perfectly fine. It's just that the design of the rear sight makes it a pain, but that's retro fixed sights for you. I've bought this for 2 separate uppers, and I'm buying a third right now for a buddy who's doing a retro build. Yet to have an issue with them due to missing parts or anything like that.