Spring clamps are all over the place. You can get a bundle of these in a mesh bag for under 10 bucks. Every big box and hardware store has spring clamps, most are cheap. The problem with these ultra-cheap clamps is the inconsistent quality; you may get a few good ones but just as many bad ones. The bad ones have weak springs and poor jaw alignment that make them all but useless. These Irwin clamps are more expensive but you get what you pay for here. I have a half-dozen of these and they're all consistent in gripping force (stronger than most) and build quality. They do have pivot tips that differ from the picture; they work just like most of the other resin clamps you'll find.