Material: chrome-vanadium. sizes: 3 / 4-2 " (19-51mm) Adjustable wrench head, high torque, durable. Used on lever bolts, screws, nuts and more. Note: When choosing the wrench, measure the outside diameter of the round nut. Then you can choose a larger wrench to easily bend the nut. Size: Round Head, 3 / 4-2 " (19-51mm) Round head: 3 / 4-2 " Suitable for round nut outside diameter 19-51mm