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. Easy to install and use. - Material: Metal and Plastic. - Made of premium material, very sturdy and durable. - 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- Portable and compact, very space saving. - Can be clamped onto or screwed onto your greenhouse frame. Notice: - Do not use this opener anywhere the temperature will exceed 50 C. - Please ensure your greenhouse window can be opened freely by at least 45cm. - Please make sure that your greenhouse windows can open freely and there are no obstacles. - The maximum weight of the ventilation window does not exceed 7 kg. Quantity shipped: 1 piece Product color: black Product size: about 33.5cm long Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.