The spring-loaded piston is compressed under the workpiece. After the workpiece is clamped, air is applied to lock into position. Release the air to unlock the piston. The piston is tapped to accommodate a work support tip. The support capacity is up to 16 lbs. The body is made from 5052A aluminum with an anodized finish. The piston and locking shaft are made from 1045 steel with an electroless nickel plated finish. The cylinder is made from A5056 aluminum with an anodized finish.