Spikes Tactical BAR2 9in Rail - The Spike's Tactical LW BAR2 is a 1pc free floating quad-rail that is machined from 6061-T6 aluminum with a barrel nut machined from 7075-T6 aluminum and finished in type III hardcoat anodizing on the rail and barrel nut. The main benefit of the BAR rail is to those who wish to have a suppressor inside of the rail. The BAR rail also offers excellent heat ventilation, built in anti-rotation tabs to keep the rail and even the barrel nut from coming loose, and of course; sexy styling. 1 Piece Free Float Design Rail - 6061-T6 Aluminum 7075-T6 Aluminum Barrel Nut Black Type III Hardcoat Anodized Built In Anti-Rotaion Tabs Excellent Heat Ventilation Scalloped Rails 6 Built In Q.D. Sockets (Sling Attachment Points) Continuous Top Rail Compatible With Many Low Profile Gas Blocks Barrel Nut Works With Standard USGI 3 PIn Barrel Nut Wrench Includes: 3 Black Ergo Rail Covers, 1 Barrel Nut, 1 Heavy Duty Q.D. Sling Loop, 4 Barrel Nut Shims (Three .003in And One .001in), 10 Grade 8 T-20 Torx Screws (2 Spares), 1 Tube Of Blue Loctite, 1 T-20 Torx Wrench, Instruction Sheet, Spike's Tactical Lifetime Warranty