Description: This windows opener is ideal for your greenhouse window.As the temperature changes automatically, it maintains the best growing temperature and prevents your greenhouse from overheating.As temperature rises or drops, then opener will open or close theandnbsp; greenhouse vents . Specifications: Maximum window opening: 45cm Maximum opening about: 30°andnbsp; Depending on adjustment and load Maximum opening weight: 7kg/15lb Adjustable open temperature range: 15°- 25°/60°-77F Size: 38 x 9.5 xandnbsp; 9.5 cm / 14.96 x 3.74 x 3.74 inch (appr.) Package included: 1 x Automatic window opener Important notice:andnbsp; Do not use this opener anywhere the temperature will exceed 50° (122F) Please ensure your greenhouse window can be opened freely by at least 45cm (18") Do not apply excessive loads by locking or covering window Do not dismantle the cylinder The opener CANNOT stop by manual Note: Due to the upgrade of this item, the 11th part showed in manual is not included. Please take the real one as standard.