Solar water heater Features: Tank : Inner tankfv sus304 food grade stainless steel, thickness 0.4mm Isolation layer fv high dense polyurethane integral foam, thickness 55mm Outter shell fv sus304 stainless steel 2) supporting frame: Stainless steel plate with thickness of 1.2mm 3) vacuum tubes: Hard borosilicate glass tube, 30mm hailstone resistant Diameter: 58mm length: 1, 800mm Temperature resist: -30 ~ 250 degree c 4) echo tilt: 38, 45, 50 degree 5) system pressurized runs without pressure 6) water temperature up to 95 degree c Capacity: 1) high capacity model: 18 tubes / 252 l 20 tubes / 280 l 2) high temperature model: 20 tubes / 180 l 24 tubes / 216 l 26 tubes / 234 l 30 tubes / 270 l