The "Mushroom Cap" fits a Mocal Thermostatted Adapter Plate and works with long Threaded Nipple to integrate the factory heat exchanger. -a very smart way to go that gets oil up to temperature fast without imposing too much heat burden on top. (Use our short Threaded Nipple if you seek to eliminate the factory heat exchanger.)
Note: Cap and thermostatted sandwich plate shown together. Plate is available for separate purchase and is not priced with cap.