IRWIN QUICK-GRIP 1964719 Bar Clamp/Spreader, 300 lb Weight Capacity, 18 in Max Opening, 3-3/16 in D Throat                The IRWIN(R) QUICK-GRIP(R) SL300 one-handed bar clamp provides up to 300 lb of sustained clamping force that is evenly distributed through locking swivel jaws. It is constructed with an I-beam bar to reduce flexing and bowing and has a unique pistol grip design and quick-release trigger for one-handed operation. This clamp easily converts to a spreader with a few simple turns of a Quick-Change(TM) screw.