I purchased a number of these clamps because of the size and the ability to apply and remove them with one hand if I had to hold something else with my other hand.  The clamps work as expected and hold first time, every time.  The locking mechanism works great and holds so well that it is sometimes difficult to release.  The self adjusting jaw pads allow for an uneven surface without denting the surface like a fixed pad would.  I have never been disappointed by an Irwin product and these clamps are no different.