The Sylvan Arms Folding Hinge 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 5.56 to .308 systems, as well as .223 compatible, it has standard 1-3/16 x 16 thread and does not require any additional parts to be used with standard BC 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 armorers wrench. The product does not need to be disassembled in order to install it on to your .223/5.56 to .308 & most 9mm rifle/pistol. NOTE: This item is also 300 Blackout compatible. It does not work with Silent Capture Buffer Spring or JP Enterprise Buffer System.