The Wraith Handguard was designed and built to fit most Mil-Spec AR15/M4 upper receivers. Boasting one of the easiest mounting systems to install in the industry, these M-LOK slim-line handguards provide superior fit, finish and performance.-Works with low-profile gas blocks-Seven rows of mounting surface-Streamlined 1913 picatinny top rail-Type III hard coat anodized.