ATI's 6,000-pound track modules can be retrofitted in place of tires to most machines in about six hours. These traction enhancers each lay down a 36- by 75-inch footprint, and their weight lowers the machine's center of gravity. Sprocket design places the rubber lug molded into the inside circumference of the track in compression between the sprocket and the track carcass. This allows the lug to withstand lateral forces as sprocket teeth drive against them from the side. This design also raises the track just enough to prevent the sprocket teeth from pushing into the track carcass hard enough to damage its steel reinforcement. A patented tensioning system uses dual nitrogen accumulators charged to different pressures to reduce rolling resistance and help shed debris. Estimated list price: $35,000.