... -pressurized solar water heater The CN-YS02 type has the stainless shell,so it can be used in the rain area ... tubes:15pcs,18pcs,20pcs,24pcs,30pcs3,Outer tank material:202stainless steel with 0.31mm4,Inner tank material:SUS304-2Bstainless steelthickness :0 ... ,Optional electric heater:220v-240v 1500w/3000w7,frame material :202 stainless steel8,we could product for customer'special needIt has 15years ...