This Cam locking MLOK rail from Bootleg is pretty light and easy to install. I test fitted it and it took a whopping fifteen seconds to install securely. Not too shabby.
Single large flat head screw tightens the rail onto the barrel nut.
Plastic cam cover closes on it.
Pretty simple and effective system.
Rail is thin and light.
I got the 9.5" version for an SBR build.