1、Made of quality material, durable, solid and convenient to use 2、As the temperature changes automatically, maintains the best growing temperature and prevents your greenhouse from overheating 3、Non-electric, uses solar energy, open or close the greenhouse vents as temperature rises or drops 4、Ideal for your greenhouse window 5、The temperature is automatically adjusted from 15 to 25 °C Features: Made of quality material, durable, solid and convenient to use. As the temperature changes automatically, maintains the best growing temperature and prevents your greenhouse from overheating. Non-electric, uses solar energy, open or close the greenhouse vents as temperature rises or drops. Ideal for your greenhouse window. The temperature is automatically adjusted from 15 to 25 °C. Specifications: Item Type: Greenhouse Winder Opener Cylinder Color: Sliver + Black Temperature range 15°- 25°/60°-77F Support rod total length: 33.5cm / 13.19 inch (appr.), the largest diameter: 1.5cm / 0.59 inch (appr.) Double spring window opener (closed state) total length: 32cm / 12.60 inch (appr.) (Open state) width: 24.7cm / 9.72 inch (appr.) Package List: 1 x Greenhouse Winder Opener Cylinder Notes: Do not use this opener cylinder anywhere the temperature will exceed 50° (122F). Do not dismantle the cylinder. This products need to be refrigerated before use it. 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.