The boa constrictor strap wrench is the original and best strap wrench useful for many jobs including plumbing automotive ac installationmaintenance pool pond and oil filters both strength and flexibility are provided by the braided rubber strap which fits into a slot in the handle of the tool and provides a perfect fit on the work piece provides over 2000lb of pressure without marking the workpiece with a pro use capacity of up to 190mm capacity 10mm 38in to 190mm 712in