ZEV Technologies Wedge Lock Hand Guard is the most technologically advanced hand guard on the market today. The free-float handguard attaches to the receiver by an innovative system built around a lightweight titanium barrel nut (included) and the two-piece Wedge Lock system tightens down securely with only one screw. It is machined from aircraft grade aluminum, with narrow cross-sections which provides for an excellent ergonomic grip while the M-LOK negative space mounting system provides a smooth surface. The handguard has a black hard anodized finish while the Wedge Lock system has a black nitride coating. It is not designed for a suppressor to be mounted under the hand guard. This 14.625" model with an internal diameter of 1.225" is compatible with AR15 chambered in 5.56, all mil-spec upper receivers, and low profile gas blocks.