The revolutionary patented 'GL-Shock' absorbing Buttstock contains a recoil-reducing mechanism with a built in premium silicon chrome alloy spring creating a State-of-the-Art stock for your M4/M16. Adjustable Cheek Piece with Built-In Dual Picatinny Rails allows optimal Buttstock functionality   Advantages: Unique Patented “Anti-Rattle” Mechanism Sleek New Design with No Protruding Parts,Will Not Get Caught on Gear and Webbing Unique New Slick and Quick Operated Inversed Positioning Lever Integral Ribbed Rubber Butt Pad with a Non Slip Design Integrated Quick Detach “QD” Sling Swivel Connectors on Both Sides Watertight Battery Storage for Two CR123A 3V Lithium Batteries / AA 1.5v Fits Perfectly on Both Tubes - MIL-SPEC and Commercial Aftermarket! Made from Mill-Spec Reinforced Composite Polymer Adjustable Cheek Rest with Built-In Dual Picatinny Rails Allows Optimal Buttstock Functionality  Ideal Mounting Solution for the SH-5 Specifications Weight: 14.9 oz. Width: 2.6" Height: 5.2" Length: 7.1" Height (Raised Cheek Piece): 6.4