Ideally suited for hydrostatic drive circuits which require fast warm up, controlled fluid temp and low return line back pressure. When installed in the return line of a hydraulic circuit that employs an oil cooler, will modulate fluid temp by either shifting return line flow through the cooler or bypassing directly to the reservoir. Relief valve set at 65 PSI - operating pressure 250 PSI. Proof pressure 300 PSI. Max operating temp shift temp + 75 degrees F. Max GPM flow 60.