Automatic DesignThe automatic window opener opens and closes your greenhouse window as the temperature changes automatically, maintaining the best growing temperature and prevents your greenhouse from overheating. Solar EnergyUsing the solar energy, instead of electric, open or close the greenhouse vents as temperature rises or drops. Save your energy and time, and no need for human operation. CO2 FriendlyThe window opener will be very environmental and CO2-friendly throughout its whole lifetime because there is no need of electricity in your greenhouse. Easy InstallationThe window could be clamped onto or screwed onto your greenhouse frame. Please ensure your greenhouse window can be opened freely by at least 45cm (18"). Do not apply excessive loads by locking or covering window. Hydraulic Cylinder with WaxOur core technology is the hydraulic cylinder that contains a plant-based wax, works as the greenhouse window openers thermostat, thus there is no need for electrical power supply. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.