Cummins ISX 6 Cylinder Compressed Natural Gas (CNG) Engine, Air Conditioner, Cruise Control, Power Windows, Eaton Fuller FRO-15210C 10-Speed Manual Transmission, Differential Lock, 12000 lb Front Axle, 40000 lb Rears, 3.55:1 Axle Ratio, 52000 lb GVWR, Air Ride Cab, Aluminum Outer Wheels, 275/80R22.5 Front Tires, 275/80R22.5 Rear Tires, Air Ride Suspension, 187 in Wheelbase