This is a wonderful clamp for one-handed use. It has a glass-filled nylon body, nylon jaws and a steel lock-up/quick-release mechanism. With one touch on the release lever, the jaws spring open. Squeezing the clamp translates hand pressure directly into clamping pressure (a 1:1 transfer ratio), and the clamp automatically locks at the pressure applied. The sliding jaws quickly adjust for material thickness (to about 5 1/2" maximum) and have pivoting non-marring feet with raised ribs for grip.