Specifications: 1) Relative humidity: 90% (25°C) 2) Compact construction, large torque and quiet operation 3) Short hour working system, continuous operation not exceeding 7 minutes with one phase and 10 minutes with three phases 4) Stylish, advanced structure and strong power 5) Imported electronic parts 6) Safe and stable 7) Little vibration and small power consumption 8) Light weight, easy to install, long operational life and reliable performance 9) Remote control: long distance operation 10) Theftproof and fireproof functions 11) Easy manual operation in case of power failure 12) The first power storage mechanism of its kind in China 13) Security mechanism in case that chain is broken