Features and Benefits: Compact design works great in tight spots; The small size works well with heater hose clamps; Vise opens to 1-1/2"; Tool can be left on hose during use; Tighten knurled knob by hand or use 1/4" drive ratchet; Tool is designed to relieve clamp spring pressure in very tight spots. Vise is often left in place, with the clamp compressed, during service. Tool is 3 in. long and opens to 1 1/2".Ramp on jaws guides tab of clamp into correct position and traps it in the slot for safety. Tighten knurled knob by hand or use 1/4 in. drive.