Sig 516 Extended Free Float M-LOK Handguard - Installs on factory barrel nut not included with handguard - Features a monolithic type continuous top rail. - Features five anti rotation QD sockets for push button swivels - Light weight with extremely solid lock up. - Constructed from 6061 aluminum hard coat anodized - Extends past the front sight tower for additional space for mounting accessories. - Overall length of top rail 7.25 width 1.840 height 2.17 - Weight: 8.3oz. - Five slot M-LOK compatible rail piece included. - 100 percent made in USA