Yankee Hill Machine Co Carbine Handguard, 2 Piece, Fits Colt AR-15's with Carbine Length Gas Systems and Fixed Front Sight Gas Block, Anodized Finish, Black YHM-9670-C 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.