When oil temps exceed 180 degree F, the termostatic valve closes allowing 95% flow through the oil cooler. At teps below 180 degree F, the valve is open with 90% of the oil by-passing the cooler. The remaining 10% of the oil flows through the cooler, maintaining constant system pressure, preventing air pockets and eliminating cold oil shock. It flows up to 20 gallons per minute and is rated at 200 PSI. This mounting kit containers four brass fittings,and four stainless steel hose clamps. This will autmatically regulate oil pressure, provides quicker warm-ups to operating temps, prevents over cooling in cold climates and is for use with either transmission or engine coolers. Add $25.00 for the mounting kit for this item.