stable quality acquired certification: CE,CCC,ISO9001-2008, Solar Keymark, SRCC, SGS energy saving offer OEM Evacuated tubeDia ... grade steel, anti-corrosion 1) inner tank : imported SUS-204 stainless steel 2)outer water tank: stainless steel , colored steel, galvanized ... steel 3)capacity: 200, 250 ,300,400L 4)tank diameter:410, 460 ...