The IRWIN® Original 9DR 9-inch Locking C-Clamp has wide-opening jaws to provide greater versatility in clamping a variety of shapes and is constructed of high-grade, heat-treated alloy steel for maximum toughness and durability. Its classic trigger release is designed to provide maximum locking force. Turn the screw on the IRWIN® clamp to adjust pressure and fit work. The locking clamp stays adjusted for repetitive use.