“Leapers UTG PRO US Made Mil-spec 6-position Receiver Extension Tube for AR-15” has been added to your cart. View cart HomeGun PartsAR Lower PartsAR Buffer SystemCMMG Receiver Extension Mk4CMMG Receiver Extension Mk4$36.00 CMMG Receiver Extension Mk4 Additional information UPC 816422020676 Manufacturer CMMG Manufacturer Part Number 55CA9D7 Product Type Buffer Tube Style Extension 3 in stock CMMG Receiver Extension Mk4 quantity Buy now Add to WishlistRemove from Wishlist Add to Wishlist