CALORITECH CXF Series Screwplug Immersion Heaters are used primarily for oil heating and have steel screwplugs. Low-watt density heaters are used in heavier, non-circulated oils. Higher-watt density heaters are suitable for light oils or in forced oil circulation loops. Incoloy elements are silver brazed into a steel screwplug. Application-Screwplug heaters are primarily used to heat liquids in tanks or vessels. To do so safely and reliably, the heating elements must remain fully immersed in the liquid. Liquids such as water, oils, trichloroethylene, etc. can be heated through natural convection currents created by the immersed elements. Although electricity costs are generally higher than gas or oil, a CALORITECH immersion heater is often the best choice. The electric heater provides close to 100% efficiency, is safer and easier to control and is usually cheaper to install. Terminal Block Simplifies Wiring - All thermostat-equipped screwplug heaters with moisture or explosion-proof housings feature a convenient terminal block mounted to a slide-out trolley. This unique CALORITECH feature simplifies installation and reduces maintenance. Color: Silver/Black. Material: Brass.