These handguards are designed to replace your standard plastic handguards with their 4 rail picatinny design. Simply remove your existing handguard panels and insert these in their place.Features :Lightweight aircraft grade aluminum,Total Length: 6.625" (inches),Total Weight: 10.464 OzHardcoat Anodized matte black to Military Specifications or betterThe bottom rail removes easily to accommodate accessories such as grenade launchers, flare launchers and shotgunsWill not fit Colt carbines