Product Description: Size: 33 Millimeters Product Description: Striking face wrenches are designed to be struck by a hammer on the anvil area in order to loosen frozen fasteners or to set and tighten fasteners. Anvils are proportional to opening sizes. Special heat treating provides maximum durability for long life. Straight handle design resists springing while allowing the fastener to turn more easily. Williams' expanded line of offset striking face wrenches, up to 4-5/8", provides the most extensive line on the market. Specifically engineered to hold up under the most rigorous industrial use. From the Manufacturer Snap-on Industrial Brand JH Williams 1 5/16-Inch straight pattern box end striking wrench has a striking face wrenches are designed to be struck by a hammer on the anvil area in order to loosen frozen fasteners or to set and tighten fasteners. The anvil is proportional to opening size. The special heat treating provides maximum durability for long life. The straight handle design resists springing while allowing the fastener to turn more easily. This wrench is specifically engineered to hold up under the most industrial use.