Adjustment at the touch of a button directly on the workpiece. Fine adjustment for optimum adaptation to different size workpieces and a comfortable gripping position. Self-locking on pipes and nuts: no slipping off the workpiece and low hand force required. Gripping surfaces with special hardened teeth, teeth hardness (approx. 61 HRC): low wear and reliable gripping. Box-joint design: high stability because of double guide. Reliable catching of the hinge bolt: no unintentional shifting. Pinch guard prevents operators' fingers being pinched. 18 adjustment positions. Chrome vanadium electric steel; forged, multi-stage oil-hardened.