The MRE package is meant to do the job with M4 carbines, and accommodates a fixed A2 entrance sight tower with carbine length gasoline program. It extends earlier the front sight foundation, giving extra rail space with the mounting of tactical add-ons. Contains a few KAC 11 Rib Rail Panels. https://johnathanjvhai.qodsblog.com/26601687/5-simple-statements-about-knights-armament-m4-quad-rail-explained