The IRWIN 224134 Quick-Grip Clutch Lock Bar Clamp locks materials in place until you're ready to release them. It relies on a sturdy bar to withstand pressure without cracking or breaking. This Irwin bar clamp features large clamp plates and it distributes pressure over a large surface area when you lock it in place. Its throat sustains this grip and prevents materials from sliding out of position. One handle adjusts the pressure for tight holds and a clutch releases everything when you finish with your task.