Tacstar stock adapter to mil- spec ar-15 for rem.870 12ga. FEATURES:- Material: ABS Polymer-Adapts AR-15 MIL-Specs and Pistol Grips to fit Remington 870 12 GA. shotgun.-Designed to allow the use of a AR-15 telescoping stocks and pistol grips on your shotgun.-Made of a tough die cast metal alloy that also provides greater strength, and additional weight to reduce felt recoil. Other Features: Adapts ar-15 mil-spec stocks and pistolgrips to fit remington 870 12ga.Shotgun.