Features Automatic Adjustment - The automatically adjusted temperature is 20 to 25°C.As the temperature changes automatically, maintains the best growing temperature and prevents your greenhouse from overheating. Easy to install - Equipped with screws, can be installed directly with clamps(not included) or screws, very simple and convenient. Use Solar Energy - No battery or power required, uses solar energy, open or close the greenhouse vents as temperature rises or drops. Universal Vent Opener - Applicable to most windows, the maximum weight of the ventilation window is less than 7 kg can be used with confidence Can Be Used Onto Greenhouse Frame - Can be clamped onto or screwed onto your greenhouse frame. Product DescriptionTOPINCN Greenhouse Window Opener Automatically Prevent Overheating Vent Autovent Solar Heat Energy Sensitive Automatic Ventilator Greenhouses Roof