Three all-metal wheel construction. Familiar left-right-left dialing sequence, and one-handed operation for convenience. Tweny man-hours of resistance to expert manipulation. Built in thermal protection provided by an integral thermal relock component. Key changeable wheel design for simple combination changing. Stainless steel lock bolt is strong enough to resist more than 600lbs. of force. Incorporates SGs patented, time-tested torque adjuster to allow precise setting and maintenance of wheel pack torque. The lock case uses SGs Magic Module footprint for ease of retrofit on existing containers.