Guntec Castle Nut Wide Heavy Duty Features The Guntec USA Castle Nut Wide Heavy Duty is machined from steel and treated with a nitride finish giving the part strong resistance to corrosion and wear over repeated use. Its extra wide design increases the contact surface between the nut and the receiver extension end plate producing a stronger more durable hold than a standard profile castle nut. This added surface area helps the nut resist loosening under the recoil impulse generated during extended shooting sessions. Steel construction ensures the nut holds its threads cleanly through repeated staking and torquing during installation. Compatibility with both Mil-Spec and commercial buffer tubes means this castle nut fits the vast majority of AR-15 builds without requiring a specific tube diameter. Builders upgrading a stock setup or assembling a custom lower receiver can rely on this heavy duty nut to secure the buffer tube firmly in place. The black nitride finish also matches the typical black hardware found throughout most AR-15 builds keeping the overall look consistent. Made in the USA this castle nut gives AR-15 owners a durable drop in upgrade for their buffer tube assembly available for sale at GrabAGun. Guntec Castle Nut Wide Heavy Duty Specifications Manufacturer: GunTec Model: Castle Nut Wide Heavy Duty Material: Steel Finish: Nitride Color: Black Compatible Hosts: Mil-Spec/Commercial Buffer Tubes Country of Origin: Made in the USA Available At: GrabAGun