household use, bathing no.:3-4, preservation time: 72 hours, certification:CE,ISO9001-2008,SRCC,Solar Keymark,UL,SABS offer OEM Name: Non-Pressure Solar Water Heater(Stainless Steel Series) a) Item no.: RS-SS-NPb) Inner tank material: SUS304-2B, thickness: 0.4-0.8mm, diameter: 320, 360mm.c) Outer tank material: stainless steel,diameter: 420, 455, 460, 470, 480, 500.d) Insulation layer: high ...