Specifications: Greenhouse Window Opener Kit Material: Aluminum Alloy Fully adjustable between 20 - 25 ° C (68 - 77 ° F) Maximum window opening: 45cm / 18 inch Maximum opening weight: 7kg/15lb Size: Approx. 38x9.5x5cm / 15.0x3.7x2.0in Package: 1 x Automatic Window Opener Kit Automatic Design: The 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 Energy: Using 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 Friendly: The window opener cylinder will be very environmental and CO2-friendly throughout its whole lifetime because there is no need of electricity in your greenhouse. Easy Installation: The 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. Strict Quality Control: The greenhouse window opener is manufactured to standard specifications, in strict accordance with factory quality control. So there is no need to worry about the product problems.