Ingenious temperature-sensitive automatic vent opener can automatically open and close window frame, really works well in maintaining the greenhouse within the preferred temperature range. The vent opener starts opening between 15-25 (60-77), depending on how you have adjusted the cylinder. Features: Automatic Vent OpenerGreenhouse windows opener can open and shut your greenhouse window automatically to maintain the best-growing temperature and prevents your greenhouse from overheating. Wide ApplicabilitySingle spring vent opener can be closed manually and easy to install, fit for most of aluminum frame greenhouse. Adjustable Temperature RangeTemperature range is adjustable from 15-25 (60-77) by turning the cylinder, maximum opening at about 30/86 (depending on adjustment and load). Iron ConstructionDurable and rust-proof Iron windows opener with paint spraying for last long time use. 15lb Load BearingUse the Standard Vent Opener to lift up to 7kg / 15 lbs. Specifications: Material: Paint Spraying Iron Color: Silver Star open at:15-25 (60-77) Fully open at: 30/86 Max open distance: 45cm/17.71inch Load bearing: 7KG / 15lb Cylinder Length: 33.8cm / 13.3inch Package Size: 38*10*5cm / 14.96*3.93*1.96inch Package Weight: 520g / 1.14lb Package List: 1 * Automatic Vent Opener 1 * Package of Accessory 1 * Manual (English) Note: Do not heat to more than 50(122). Do not dismantle the cylinder. Do not apply excessive loads by locking or covering the window.