BREATHER VENT COMPRESSION SPRINGS PISTON BALL BEARINGS SPLIT COLLAR MANUAL RELEASE CAM A series of equally spaced compression springs provide the rod lock actuating force. Dozens of ball bearings separate a split, tapered collar and piston. The piston travels up the ramp on the collar under spring force and causes the split collar to constrict on the rod. Air pressure applied to the opposite side of the piston compress the springs to release the grip on the rod. Select models have a manual release feature to disengage the rod lock without air pressure. The mechanism is cam operated, turned with a wrench and is a “default-to-lock” function. As long as a force is applied to the wrench the rod lock is disengaged. With no force applied the rod lock “defaults” to the engaged position.