Leapers, Inc. - UTG Model 4 Combat Ops S1, Stock, Ambidextrous Sling Loop and Reversible QD Sling Swivel Housing, Polymer Stock Only, Black Finish RBUS1BMS The UTG PRO Model4 Combat Ops S1 Mil-Spec Butt Stock is a collapsible" AR/M4 style stock constructed of weather proof and rugged high impact polymer. This 6 position stock is designed for heavy duty operations and is made with the tightest tolerances for the most secure fit and silent performance. It has a thick rubberized recoil pad" reversible QD sling swivel housing" and an ambidextrous sling loop attachment. Chamfered edges and slanted cheek rest provide the comfort you're looking for.