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: 38°C / 100°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 Cylinder 1 x Window Opener Bracket 1 x English Manual 8 x Screw 4 x Accessories ★ Solar Heat Sensitive Window Opener - 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, the ideal growing temperature is maintained and the greenhouse is prevented from overheating. ★ Automatic Temperature Sensor & Double Spring Controlled - Automatic temperature control sensor cylinders that allow roof vents to open and close at the appropriate time to ensure adequate airflow. When temperature above 25°/77°F, the window opener will keep opening.Fully open temperature at 30° (86°F) or above; once temperature drop to about 15°/59°F, the window opener will totaly close. ★ Quick Open And Close - Automatic vent opener opens and closes greenhouse window quickly and can be clipped or screwed onto your greenhouse frame.(Do not apply excessive loads by locking or covering window.The automatic ventilation window opener in the greenhouse cannot be used in an environment with a temperature higher than 50°) ★ High Quality Greenhouse Window Opener - Auto Vent Opener Automatic Greenhouse Window Opener is made of aluminum and stainless steel, which is durable and weather resistant for long term use. All parts corrosion resistant, Resists wind damage when opening and closing ★ Specification & Application - Window Bracket: 33.5 x 4.5 cm / 13.2 x 1.8 inch, Temperature Sensor Cylinder: 34cm / 13.4 inch. Maximum Opening Distance: Approx. 45cm/18 inch, Fits Weight: Window or vent up to 7kg/15lbs (Suitable for any and most greenhouses)