The Lage 1913 left folding stock is designed for use with receivers and firearms that have a Picatinny M 1913 rail mounting point. This includes the Angstadt Arms MDP-9, BRN-180 Lower Receivers, Sig Sauer MCX, MPX Copperhead, and many other platforms that utilize a rear picatinny (pic rail) mount. This stock is a combination of Lage's Picatinny M 1913 Rail Stock Adapter, folding mechanism and Polymer Stock. Includes everything you need to mount to a folding stock to your 1913 picatinny end rail. Features: Color: Black 7.5" Buttstock Stock adapter and folding mechanism manufactured from 6061 aluminum and finished in flat black anodize Buttstock is manufactured from glass reinforced nylon, this stock is not only strong, it is more comfortable to shoot in extreme cold or heat than an aluminum stock. Stock can be configured to fold to the right side by reversing the folding mechanism Easily un-folds and solidly locks in place Sling mount on the top rear of the buttstock weight: 13.4 oz