For a truck and trailer set that has one height control valve on the drive axles and one height control valve on the trailer axles, use a gauge with two air inputs. For a truck and trailer set that has two height control valves on the drive axles and one height control valve on the trailer, use a gauge with three air inputs. For a dedicated B-Train that has two height control valves on the drive axle and one height control valve on each of the trailer axle groups, use a gauge with 4 air inputs. The estimated steer feature and weight values for the entire truck and trailer set are can also be displayed. Extra features include a PIN lock out code, multiple language selection, easy to use touch screen, and adjustable back light.