Deno Compact Non-pressurized Solar Water Heater with high quality 1. CE ,ISO CCC 2. 5 years guarantee 3. OEM ... solar vacuum tube, water tank, stand. 2. Using solar vacuum tube is very high efficiency.3. The complete system doesn't need ... .4. Easy install, easy operation, fashionable.5. Well wind, snow and hail resistance.6. 72 hours heat preservation.Working Principle:This ...