Here we have is a brand new , aftermarket , nismo , nissan s13 silvia / 180sx , S14 / S15 200sx , SR20DET engine cooling thermostat , purpose of this item is from the factory thermostat opening up at a certain 85 degrees celusis for example , the nismo item would open up 10 degrees earlier to keep the engine cool so that the stock item doesnt get too hot too quick , so nice way to keep the cooling system under control.