Function: 1. Greenhouse window opener kit, adopts aluminum alloy material, with good durability and stability. 2. When the temperature changes automatically, it can automatically open and close to prevent the greenhouse from overheating. 3. With springs and support rods to provide extra protection against wind damage. 4. It can be directly crimped or screwed do greenhouse frame, easy to install and use. 5. Maintain optimal growth temperature in the greenhouse and ensure an appropriate growth environment. Specification: Item Type: Window Opening Kit Material: Aluminum Alloy Kolor: black Applications: Greenhouse, Household Bearing weight: 14kg.31lb Opening force: 7kg do 15lb Closing force: 0,5kg do 1lb Product operating temperature: 17-25 Maximum opening temperature: 30 Maximum opening distance: approx. 45cm do 17.7in Weight: approx. 570g do 20.1oz Window opener size: approx. 31.5cm do 12.4in Cylinder size: approx. 34cm do 13.4in List of packages: 1 x Accessory Set (12ks) 1 x English Manual 1 x Opening windows 1 x Cylinder 1. Please allow 0‑1 inch error due to manual measurement. 2. Please take the real one as standard.