The Sylvan Arms Folding Stock Adapter allows you to fold your stock and significantly reduce the length of your rifle for easy stow and travel. Specifically designed for gas piston and direct impingement systems .223 / 5.56 to .308 systems it has standard 1-3/16 x 16 thread and does not require any additional parts to be used with standard Bolt Carrier Groups. It is CNC-machined in the USA from 7075 Billet Aluminum making it uniquely lightweight and corrosion resistant. This assembly weighs only 6.0 ounces. No special tools required; only a standard armorer’s wrench. The product does not need to be disassembled in order to install it on to your rifle/pistol. Simply screw on fold and carry! Now Compatible with Silent Capture Buffer Springs!