This tool is a heavy-duty, single-ended box wrench featuring an anvil or striking face at the opposite end. It is engineered to be struck with a hammer to tighten high-torque fasteners or loosen "frozen" or rusted nuts in severe industrial environments. Opening Size: 1-1/2 inches Point Profile: 12-pointPattern Style: Straight handle Design Features: Built with a "lobular" opening configuration that drives force against the flat surfaces of the fastener instead of the corners, effectively preventing rounding.