Designed in conjunction with Maxim Defense, the SBPDW Pistol Stabilizing Brace is 3-position adjustable and compatible with mil-spec bolt carrier groups and carbine buffers. Features: 3-postion adjustable, Complete assembly, ready-to-install, including a proprietary buffer tube (does not include buffer/spring). Compatible with mil-spec bolt carrier groups and carbine buffers/springs. QD attachment point at 6 o’clock position on housing. ATF compliant, US veteran designed and proudly made in the USA. Product Includes: complete assembly, adjustable nylon strap. Additional Information: The end plate and castle nut are integral to the assembly. Castle nut wrenches are often steel. The SBPDW buffer tube/castle nut assembly is aluminum. Care must be taken during installation / removal to avoid damaging the nut. Space between rods is 1.175. Depth of the tube is 6.920. Not compatible with Freedom Ordnance FX-9 lowers or SIG M400/516 lowers with integral QD sockets.