The MRE kit is meant to function with M4 carbines, and accommodates a hard and fast A2 entrance sight tower with carbine length gas method. It extends earlier the front sight foundation, providing additional rail Place for the mounting of tactical components. Consists of 3 KAC eleven Rib Rail Panels. https://knights-armament-m4-quad19528.kylieblog.com/27024441/what-does-kac-ras-rail-mean