Knipex Cobra. Press the button to adjust to the workpiece. Fine adjustment for optimal adaptation to different sizes of workpieces and a comfortable grip width. Self-locking on pipes and screws: no slipping on the workpiece and minimal hand force required. Gripping surfaces with specially hardened teeth, tooth hardness approximately 61 HRC: high wear resistance and stable grip. Reliable capture of the hinge pin: no unintentional slipping. The pinch protection prevents the operator's fingers from being pinched. Capacity for half-moon, capacity in square millimeters, square drive capacity, square capacity, step-shaped square capacity, triangular capacity, clamping width for hexagonal, clamping width for round, clamping width for square.