Specifications: Greenhouse Window Opener Kit Maximum window opening 45cm Maximum opening about 30°, depending on adjustment and load Maximum opening weight 7kg/15lb Adjustable open temperature range 15°- 25°/60°-77F Package: 1*Automatic Window Opener Kit Notes: Do not use this opener anywhere the temperature will exceed 50° (122F) Please ensure your greenhouse window can be opened freely by at least 45cm (18") Do not apply excessive loads by locking or covering window Do not dismantle the cylinder The opener CANNOT stop by manual Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. 【Durable Material】Aluminium and stainless steel material, No worry corrosion. 【Automatic Adjustment】As the temperature changes automatically, maintains the best growing temperature and prevents your greenhouse from overheating. 【Environmental Protection and Energy Saving】Non electric, uses solar energy, open or close the greenhouse vents as temperature rises or drops. 【Easy to Install】Easy to fit onto your Greenhouse vent or window using supplied screws and clamps or your own fasteners into pre-punched holes. 【Note】Please ensure your greenhouse window can be opened freely by at least 45cm (18").