For Oils & ATF up to SAE 40 weight. Calibrated in U.S. Gallons, 1/10 gallon graduations. 1000 psi max Pressure. Meter totals to 999.9 gallons, resettable with non-reset totalizer on 6" dial face. 1" NPT)f) inlet & outlet. For consumer use only, not intended for resale measurements.