The IRWIN Quick-Grip Hybrid Clamp Provides the Ability to Achieve 300lbs of clamping force with the Trigger Handle; 825lbs of clamping force with Screw Handle. Rapid Switch between Clamp and Spreader. Combine two Hybrid Clamps together with provided fasteners at 2 threaded loactions on Bar for additional length - Must use both provided fasteners when coupling clamps.