RINGLOCK FRAME: STEEL PLANK,DOUBLE LEDGER,SINGLE LEDGER,STANDARD,DIAGONAL BRACE,SCREW JACK,EXTENDED BRACKET. RINGLOCK FRAME IS ASSEMBLED BY STEEL PLANK,DOUBLE LEDGER,SINGLE LEDGER,STANDARD,DIAGONAL BRACE,SCREW JACK,EXTENDED BRACKET.THIS KIND OF FRAME IS USEFUL AND HARD CONVENIENT. RINGLOCK FRAME