... .Good quality and the export carton 2.The copper coil is the TU1 and 45 degree frame 3.Three element c Solar water heater ... not harmful to health.The details of material:Evacuated tube: High quality borosilicate glass 3.3, Φ47×1500, Φ58×1800/2100, Φ70 ... 225L 250L 300LAuxiliary tank capacity: 5, 8, 10, 20L Integriative Non-pressurized solar water heater SD-T with assistant tank 5L