Surecal 12 volt / 240 volt twin immersion heater element with 2-1/4" BSP male thread. Rated 300 Watts on the 12V side and 750 Watts on the 240V side. The immersion has a high quality heavy duty 20 amp working thermostat. An independent secondary safety stat that is set at a much higher temperature so the engine doesn't trip the stat unnecessarily. This would happen with a standard domestic immersion. It is made of incoloy for a longer service life and suitable for hard water conditions. Comes with an O-ring seal for easy installation.