Use wrench to securely fasten Band-it® style free end clamps, roll band and clips or Band-it Jr.® style pre-formed CV Boot Clamps. The tool is used by turning the winding mandrel with a 1/2" socket, wrench or by hand. The mandrel tightens the clamp, holding it in place until the ears of the clamp are folded down. Use built in cutter to remove excess band material.