Description Ideal for your greenhouse window--opens and closes your greenhouse window 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. Feature - Color: As shown- Material: Galvanized Plate- Size: 34 x 12x 5cm- for your greenhouse window--opens and closes your greenhouse window 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- Including fittings & installation manual- Can be clamped onto or screwed onto your greenhouse frameNotice: - 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 manualPacking list: 1 x Automatic Vent Opener