... . OEM service Compact Non-pressure solar water heater for family useFeatures:1. This system consists of solar vacuum tube, water tank, stand ... hail resistance.6. 72 hours heat preservation.Working Principle:This system uses the thermosiphon principle, Solar vacuum tube is pluged into ... : 9001:2000, CE.5. OEM: Welcome.6. Warranty: 5 years for complete system,7. MOQ: 10 sets8. Delivery time: 10 days ...