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 OpenerMaterial: AluminumWindow Bracket Product Size: Approx. 33.5 x 4.5 cm / 13.2 x 1.8 inTemperature Sensing Cylinder Product Size: Approx. 34cm / 13.4inWeight: Approx. 436g / 15.4ozStart Opening: 25C (77F)Start Closing: 15C (60F)Open Temperature: 30C / 86FMaximum Opening Distance: Approx. 45cm/18inFits Weight: Window or vent up to 7kg/15lbsApplicable: Suitable for any and most greenhouses.Package List:1 x Cylinder1 x Window Opener Bracket1 x English Manual8 x Screw4 x Accessories