This receiver extension is designed to work with Mil-Spec dimensioned M4/AR-15 type collapsible stocks. It also can be utilized as a replacement receiver extension for the AR-10 rifle.

Features :

• Six position receiver extension made from impact extruded 7075 T6 aluminum
• Hard coat anodized
• Positions are numbered and are visible through the witness hole on most stocks
• Snag-free sliding of the buttstock