... Name: Non-Pressure Solar Water Heater With Auxiliary Tank(Colored Steel Series) a) Item no.: RS-CS-NPAb) Inner ... 0.8mm, diameter: 320, 360mm.c) Outer tank material: colored steel,diameter: 420, 455, 460, 470, 480, 500.d) ... high density polyurethane foaming, thickness: 50-60mm.e) Bracket: colored steel.f) Auxiliary tank capacity: 5, 8, 10, 20L.g ...