flat panel solar geysers 1)OEM is available 2) reasonal price 2) CE, solar water heater, ... tank: Inner tank material:Tainless steel SUS304-2B,0.4mm thicknessOuter tank material:Color steel or stainless steel,0.4mm thicknessInsulation layer:Polyurethane foaming ... sheet and electrostatic plastic-sprayed, Thickness: 1.5mm. If stainless steel, thickness is 1.2mmAngle of frame:27°,30°,38°,45 ...