The characteristic: 1 The water is heated by the heat pipe rapidly. 2 There is no water in the vacuum tube,so the tube will not break in the winter. 3 It can be combined with the architecture perfectly. 4 It can be combined with existing pipeline. 5 It will be affected by the local water quality,it does not suit hard water. 6 It can still operate in the event of occasional tube breakages. The details of material Outer tank: Alnico 1.5mm Manifold:22mm thickness 2mm