Large Jaw Locking Pliers is used to handle large-sized work pieces. It has unique jaw shape opens to 3-1/8″, large enough to handle most situations requiring a large wrench. An adjusting screw sizes the tool to the job, and the guarded release trigger prevents dangerous accidental unlocking as well as pinching. Tool locks on instantly and releases quickly and adjusts to pliers action. It permits user to put tremendous pressure on four points of any style nut or bolt head. Irwin tools are made of only the finest materials, manufactured to exacting tolerances.