Facet mounted process with an built-in MILSTD 1913 rail piece for sighting systems. Suitable for use with the M203. Heatshields In Handguard – You'll find heatshields on the inside with the handguard to shield the user during prolonged lengths of firing their weapon. Posted by Brett H on 23rd May https://lukasblqfk.blogdigy.com/new-step-by-step-map-for-knights-armament-m4-quad-rail-44030200