The Mark is a battery-operated, portable device that uses visual and audio alerts to help drivers make tandem axle adjustments. The Mark consists of two pieces – a trailer unit and a ground unit. When the two become aligned in the proper position, the unit will alert the driver. The Mark can be used in all weather conditions and requires no wires.
DOMINION SPECIALTY TOOLS, www.ownthemark.com, (800) DST-5183