Package Include 1 x Automatic Window Opener Features - Non electric, uses solar energy, open or close the greenhouse vents as temperature rises or drops. - Material: Stainless steel - Size: 34.00X1.50X1.50cm/ 13.36X0.59X0.59in - High sensitive, automatic respond to weather changes, so you don' t need to stay near the greenhouse. - This is a replacement cylinder for automatic window opener. - Color: Black - Great for most greenhouse to open or close window automatically. - Time and labor saving, also can supply a better temperature condition of plant' s growth. Goods Description for your greenhouse window-- opens and closes your greenhouse window as the temperature changes automatically, maintains the best growing temperature and prevents your greenhouse from overheating.