1 Steel, Stainless steel, copper, or incoloy sheathed element. 2 Element wire situated in proximity to outside surface for maximum heat transfer and minimum internal temperature while preserving good dielectric qualities. 3 Pure magnesium oxide compressed to an optimum density for best heat transfer and electrical insulation at elevated temperatures. 4 Weld connection. 5 Cold pin. 6 Insulator. 7 Standard post terminal.