OTC Tools 4277 50 GPM Hydraulic Flow MeterTests hydraulic oil circuits on your machinery with high accuracy and Measures flow from 4 to 54 gpm Flow Accuracy to + 4 percent of full scale and Pressure accuracy of + 1. 6 percent of full scale Pressure range up to 6,000 psi and Temperatures up to 230 deg F Standard burst disc protection system prevents spillage of hydraulic fluid in the event of an overpressure condition Accommodates bi directional flow, reads flow in one direction and Port is 1