Rmrcc is a cool design - Trijicon RMRcc Adjustable 1x13 mm 6.5 MOA Red Dot Sight

its made by trijicon so the name speaks for itself, its bright, tough, and does the job great... the only reason for the 4/5 is the mount support kinda sucks. it is NOT the RMR footprint so its not easily/ readily available on anything and if you dont want to mill your slide you have to use adapter plates. i hated the adapter plate on my sig so i ended up getting the trijy lower 1/3 mount and put it on a pdw, it works great for that but i did spend a few hundred bucks on different mounts before i decided to put it on the rifle.