This is a LBE Unlimited Accessory, model ARHCR.
The LBE Round Handguard Cap fits .750 Barrels. The hand guard cap installs behind your FSB (front sight base). Original style hand guards and many aftermarket style handguards require a round or triangular cap. LBE Unlimited is a leading producer of US Made gun parts and accessories.
Features:
LBE AR Hand Guard Cap Round Fits .750 Diameter Barrels;MADE IN THE USA
