Like all PEAK Fishing products, the C-Clamp is rigorously engineered for maximum performance and durability. The clamping jaws ride on 2 precision guide pins keeping the jaw faces parallel. Unlike a typical clamp screw, there is no rotating clamp pad causing your vise to "oewalk" as it's clamped to the table, and it won't scratch or scuff the finish. The rabbeted face engages the edge of your table, so your vise won't rock. Works with '3/8? shafts and the Clamp will also accept our Accessory Post. The lower jaw can be flipped for clamping onto surfaces from '11/16? to '2-1/4?. Now you can mount your vise on anything from a banquet table to a picnic table.