Commercial water immersion heaters :- These heaters are made of 
one Copper sheathed Tubular heating element filled with high grade
insulation powder & Heating wire coil at the centre which is brazed to
a Brass flange. Heaters are nickel chrome plated and are provided with 
earthing Terminals. A metallic cap is provided for protection of Terminals.
  Uses :- Light duty (intermittent) boilers, Washing machines, Geysers, 
Coffee urns, Sterilizers and for other commercial purposes.