Luth-AR’s MBA-3 Fully Adjustable Carbine Stock Assembly Fits AR-15 & AR-10 Commercial and Mil-Spec Buffer Tubes. It has a 3-axis adjustable butt plate, a picatinny rail on the bottom rear of the stock body and an adjustable cheek piece. This fits all .223 and most .308 AR carbine style rifles. It is constructed of strong glass filled nylon and is easy to replace and quick to install.