The FS1913(TM) features a low-profile, left side-folding strut design compatible with all platforms using an M1913 (Picatinny) interface at the rear of the receiver. This complete assembly provides pull-through opening and a secure lock-up when extended. Advanced steel hinge design locks in both folded and extended positions Pull-through design offering quick deployment With the 6061 aluminum strut Complete assembly Adjustable nylon strap