... type has the stainless shell,so it can be used in the rain area Manufacturer non-pressurized solar water heater 1,vacuum ... tube length:47/1500mm,58/18002,vacuum tubes:15pcs,18pcs,20pcs,24pcs,30pcs3,Outer tank material:202stainless steel ... ,Optional electric heater:220v-240v 1500w/3000w7,frame material :202 stainless steel8,we could product for customer'special needIt has 15years ...