Jaws on all are hardened and with a few turns of the binding nut, a firm grip may be obtained. Insulating PVC handle which is octagon shaped, preventing them from rolling when laid down. Hole extends through the full length of the handles so that wires of any length and any diameter up to the full size of the tool can be held. For securely holding small stock, taps, drills, reamers, scribers, wire, small files, and other tools.