Replacement cylinder for automatic window opener. High sensitivity, automatic response to weather changes, so you don't have to stay near the greenhouse. Non-electric, uses solar powered, opens or closes the greenhouse vents when the temperature rises or falls. Automatic greenhouse window roof vent opener is ideal for most greenhouses opens or closes the window automatically. Saving time and labor can also provide a better temperature condition for plant growth. Features: < p>1. This is a replacement cylinder for automatic window opener. 2. High sensitivity, automatic response to weather changes, so you don't have to stay near the greenhouse. 3.Non-electric, uses solar energy, open or close the greenhouse vents when the temperature rises or falls. 4. Automatic window roof vent opener is ideal for most greenhouses to open or close the window automatically. 5. Saving time and labor also can provide a better temperature condition for plant growth. Condition: 100% Brand New Material: ABS < p>Black color Temperature range: 20~25/68~77 Size: approx. 33*1.5cm/12.99*0.59in Package Included:1 x Window Opener Cylinder Only Note: 1. Please allow 0-2cm error due to manual measurement. Thanks for your understanding. 2. 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.