Manufactured from Drop-forged Steel and heat treated for strength and durability. serrated jaws for maximum grip. The design has been made from 4-6 rivets making it sturdy and you can unlock the jaws by a simple squeeze of the release handle. Quick release levers for rapid action and thumb screw knobs to adjust lockjaw capacity The knurled adjustable screw at the base allows fine control and adjusting even in oily conditions.