SOLDNew, never mounted or used Battle Comp version 2.0 (Which allows the use of suppressors that mount on A2 flashiders). Comes with unopened shim kit. Standard AR15 threads. If you haven't heard of this compensator, check out BattleComp 2.0 SCV [BCE2.0BX] - $165.00 : BattleComp, Store and reviews at Battle Comp muzzle brake - M4Carbine.net Forums These are out of stock from the manufacturer as of 6/6 $155 Shipped to CONUS via paypal gift option or money order or FTF Salem. Trades: 9", 11" or 13" Samson Evolution, Troy TRX Extreme or Ranier Evolution rail system.