We provide you with solar water heaters in China the best quality and best prices, and a variety of certified products 1Vacuum tub:High boron-silicon glass,magnetic-controlled splash double-tap cooper Nitrogen/aluminum absorption coating2Tanker:stainless steel outer tanker, crystal inner tanker3 Insulating: polyurethane ,after sunshine water temperature become 45-65in winter ,60-95 in summer. ...