Leapers, Inc. - UTG Model 4 Combat Ops S1, Stock Kit, 6-Position Mil-Spec Stock Assembly, includes Extension Tube, Buffer, Buffer Spring, Tear-drop Ring and Castle Nut, Black Finish RBUS1BM The UTG PRO Model4 Combat Ops S1 Mil-Spec Butt Stock Kit is a collapsible" AR-15/M4 style stock constructed of weather proof and rugged high impact polymer. This six-position stock is designed for heavy duty operations and is made with the tightest tolerances for the most secure fit and silent performance. The rolled threads on the mil-spec buffer tube provide a precision fit for a rock solid mount. It has a thick rubberized recoil pad" reversible Quick Detach sling swivel housing" and an ambidextrous sling loop attachment. Chamfered edges and slanted cheek rest provide the comfort you're looking for. Upgrade your AR-15 platform rifle with the Model4 Combat Ops S1 Mil-Spec Butt Stock Kit from Leapers UTG.