Bought 2 of this size in a set with 2 mini clamps (about a 4 inch clamping spread), a couple of years ago, and don't know how I survived without them.  Clamps I've tried in past take more hand strength than I have just to open them, so they're useless to me, taping or weighting just doesn't work for many things.  I've used these often for 'crafty' things or repairs, but recently used them to hold 4 ft x 8 ft boards in place while securing them with screws.  Wow!  Had no idea they held so well.  Very handy because you can clamp and release with one hand.