The FLOMEC LM51DN Digital Lube Meter Series is an electronic disc meter for use with engine oils, transmission fluid (max viscosity SAE 140), and antifreeze. The LM51DN can measure a flow range of .25-8 GPM (1-30 L/min). Measures in gallons, litres, pints, or quarts. DO NOT use with excessively dirty fluids, or fluids with particles without installing a filter.