... free 3.CE/CCC certificated 4.OEM available TongHuan solar energy water heaterTube Specification:47*1800mm cu/ss/al coated, ... both flat and inclined roof , thickness:1.2mmDescripitionSolar water heating systemMaterial of out tank0.31-0.4mm thickness ... ,overflow,water inlet and outlet,electric heaterWelding:Argon arc weldingFastening pieces:Made of stainless steel screw TongHuan solar energy water heater ...