Specification: Material: Galvanized aluminum plate Max window opening: 45cm Max opening weight load: 7kg Adjustable open temperature range: 10-25 Weight: 505g Package includes: Greenhouse window opener * 1 Installation parts * 5 Automatic window opener, your plants will be optimally ventilated by temperature-controlled opening & closing. The window opener works in a temperature range of approx. 10 C to 25 C. When the temperature changes, the automatic window opener's piston works, causing the window to open or close. You can continuously adjust the opening angle by turning the cylinder and thus achieve the correct ventilation for your bed. Environmentally conscious pre-programmed: the window opener does not require electricity. Ultra-light Easy to transport thanks to the ultra-light and practical design and perfect for all windows of standard aluminum garden houses and greenhouses.