This AR-15 M4 carbine 6 Position Retractable Stock recoil pad slip-on rubber butt pads is designed for standard AR-15 6 Position Collapsible Stocks. Rubber butt pad design provides added texture for greater control and support and easily slips on and off. Fits most 5" Butt-stocks like Colt, Leapers Utg, Tapco, T6 Stock, Ruger AR and most aftermarket Shotgun and Rifle 6 Position collapsible stocks. Fits 5 inch butt of stock. Be sure to measure your butt-stock before ordering.