Features:Holds up rafters and joists, eliminating the need for two peopleAutomatically levels the crossmember with the rimjoist or ledger giving the framer a "hands free" position while installing the joist hanger or other connectorsClamps down on Hardware Plus fromthe top or the bottom and holds lumber tightReusable and made of zinc plated durable steelFor all 2x wood framing or lessDecking, roofing, and flooring applicationsIncludes 2 joist jaws per package????What's In The Box:Deckmaster GJJ2 Steel Grabber Joist Jaw