... ,Frame with stoving varnish All evacuated tubular stainless steel Solar water heater ,SUS304-2B inner tank,advanced argon arc weldding ... , Specifaction of All evacuated tubular stainless steel Solar water heater 1.Inner tank with 0.5mm thicknes food ... offer some fittings as optional,such as:Assistant tank,controller,electrical heating element, magnesium anode etc8.Advanced automatic argon ...