Feature: 1. [Solar Powered] A mechanical system activated by heat that requires no batteries or electricity and uses solar energy to open or close the greenhouse's vents as the temperature rises or falls. 2. [Automatic Temperature Control Sensor] Automatic temperature control sensor cylinders that allow roof vents to open and close at the appropriate time to ensure adequate airflow. 3. [Premium Material] Greenhouse window opener is made of aluminum and stainless steel, which is weather resistant for long term use. 4. [Quick Open And Close] Automatic vent opener opens and closes greenhouse window quickly and can be clipped or screwed onto your greenhouse frame. 5. [Prevent Overheating] With automatic temperature changes, the ideal growing temperature is maintained and the greenhouse is prevented from overheating. Specification: Item Type: Vent Opener Material: Aluminum Window Bracket Product Size: Approx. 33.5 x 4.5 cm / 13.2 x 1.8 in Temperature Sensing Cylinder Product Size: Approx. 34cm / 13.4in Weight: Approx. 436g / 15.4oz Start Opening: 25°C (77°F) Start Closing: 15°C (60°F) Open Temperature: 30°C / 86°F Maximum Opening Distance: Approx. 45cm/18in Fits Weight: Window or vent up to 7kg/15lbs Applicable: Suitable for any and most greenhouses. Package List: 1 x Cylinder1 x Window Opener Bracket1 x English Manual8 x Screw4 x Accessories