The sandwich plate of the Grex oil cooler has an in built thermostat, to regulate oil flow. When the oil is cold, it doesnt flow to cooler to help it heat up faster, then as engine warms, it opens and cools the oil.
When oil gets over 140 deg celcius it turns to water, and can damage an engine......
Please keep offers to stated price above. If you can find one for $300 buy it, dont ask me to sell it for way less than i paid for it, unless u have something i may want to trade for.
cheers.