... Insulation:foaming polyurethane thickness:50mm or 55mm6,Optional electric heater:220v-240v 1500w/3000w7,frame material :202 stainless ... thickness galvanized steel material4,P/T relief valve ,electrical heater element with terminator5,Heat exchanger:20m long,12mm diameter,1mm ... style .5,Tank is equipped with electric water heater setting,automatic temperature controller.6,With increased anode magnesium ...