stable quality,competitive price,beautiful design Offer OEM/ODM Certification:CE,Solar Keymark,ISO9001-2008,SGS,ISO9001-2008 1.Be available in ... protection.3.Energy saving, no-pollution, no-harm4.water heater system is controlled by microcomputer.Specification:1.Vacuum tube size: 47 ... of aluminum alloy4. Hail resistance:25mm5.heat preservation: 72 hours Solar System