Side mounted system by having an built-in MILSTD 1913 rail piece for sighting programs. Designed for use with the M203. Posted by BRAD on 23rd Jan 2020 Wonderful item, suits just like a glove, strong, sound and may take a beating. Took me a minute to set up it due https://m14alcs09528.blazingblog.com/29595750/getting-my-kac-ras-to-work