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