Watlow Screw plug immersion heaters are ideal for direct immersion heating of liquids, including all types of oils and heat transfer solutions. Available in a variety of sizes, Watlow® screw plug immersion heaters feature both WATROD™ round and FIREBAR® flat tubular elements. Heating elements are hairpin bent and either welded or brazed into the screw plug—depending on element sheath and plug material compatibility. General purpose terminal enclosures are standard; with optional moisture resistant, explosion resistant and explosion/moisture resistant enclosures available to meet specific application needs. Optional thermostats provide convenient process temperature regulation.