These clamps from Armor Tool feature Armor's patented auto adjust technology. A simple turn of the thumb screw allows for quick and precise setting of clamping pressure. Simply drop them into a holes on your table and clamp. Easy to use one handed operation makes for lightning fast setups and fast un-clamping. Armor Tools are made from the finest materials available and built to last a lifetime. We offer a 100% Money Back Guarantee too! Try 'em, we know you're going to love them.