Replacement cylinder for automatic window opener. High sensitivity, automatic response to weather changes, saving you from staying close to the greenhouse. Non-electric, uses solar energy, opens or closes greenhouse vents when the temperature rises or falls. The automatic greenhouse window roof vent opener is ideal for most greenhouses to open or close the window automatically. Saving time and labor, can also provide a better temperature condition for plant growth. Features: 1. This is a replacement cylinder for automatic window opener. 2. High sensitivity, automatic response to weather changes, saving you from staying close to the greenhouse. 3.Non-electric, uses solar energy, opens or closes greenhouse vents when the temperature rises or falls. 4. Automatic roof window vent opener is ideal for most greenhouses to open or close the window automatically. 5. Saving time and labor can also provide a better temperature condition for plant growth. Condition: 100% Brand New Material: ABS Color: Black 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.