Right Weigh'S 310-54-Pp Exterior Analog Load Scale Is Designed For Tandem Axle Drive Or Trailer Suspensions With One Height Control Valve.After A Loaded Calibration At A Certified Ground Scale, The Gauge Will Reliably Display The On-The-Ground Axle Group Weight In Pounds. When Properly Calibrated And Used, Right Weigh On-Board Load Scales Are The Most Valuable Tool Available For Maintaining Safe And Legal Axle Weights.