Heckler & Koch HK416/MR556 Enhanced 6-Position Receiver Extension

Description:

Factory German Heckler & Koch 6-position commercial spec enhanced receiver extension for HK416/MR556/MR223 and other M4/AR15 type rifles. Built in drainage holes in the rear and also on the bottom for maximize efficiency. Each buffer tube has ball bearing rollers to tighten the stock when locked in position. This helps smooth the sliding action when changing between the 6 positions that also eliminates any back and forth sway from the stock.