Immersion Heater may be supplied with various junction boxes for additional terminal or lead protection. For corrosive environments, units can be supplied in other special alloys best suited to the operating conditions. The lead end of the unit may be sealed for extreme environmental conditions. Units may be supplied for three phase or three heat operation. Magnesium oxide packing. Element wire situated in close proximity to outside surface for maximum heat transfer and minimum internal temperature while preserving good dielectric qualities. Series 316 stainless steel sheath. Mounting bushing. Ceramic cap. Flexible stranded nickel alloy insulated leads or rust resistant post terminals.