Irwin 4" Quick-Grip Variable-Pressure Handi C-clamp with non-marring swivel pads. It has a variable force controlled with user's grip, the tighter you squeeze, the more clamping pressure is applied. It locks in position and has a quick release trigger that removes the clamp from work. It is a 1 hand operation. Quick-Release'trigger allows for fast and easy positioning and release. Patented ratcheting mechanism provides adjustable clamping pressure and significantly reduces hand force required to generate clamping pressure. High-tech resin construction provides strength and durability. Specially designed jaws hold odd-shaped workpieces.