IRWIN 2021406 6-Inch XP Clamp/Spreader This 6" XP Clamp/Spreader features a Power Lock System which enables the clamp to provide traditional bar clamp strength The forward pressure trigger provides one-handed convenience and speed Die cast plate increases durability that protects power tabs and the I-beam bar supports increased pressure without bowing or twisting Power Lock System Forward Pressure Trigger Die Cast Plate I-Beam Bar Applies up to 550lbs of Pressure