This unique side folding aluminum stock adapter must be mount to an AR buffer tube style threaded adapter or base and then an AR type buffer tube with a rear stock can be mounted (threaded).This part number is for side folding adapter only) Please see each specific category for the adapter for your gun. Fits Commercial and Mil Spec tubes, does NOT work with regular buffers and buffer springs. Made of light weight aluminum, finished in black oxide. Locks in the open position and closed. This part number for 1 folder. Light duty only, for light pistol buffer tube mount & Air soft only, not for use with arm braces, stabilizer blades or rear stocks, no returns if used incorrectly.