MAIN USE: Window openers automatically open and close Greenhouse window as the temperature changes, maintaining optimal growing temperatures and preventing overheating in the Greenhouse. PRACTICAL: This corkscrew automatically responds to weather changes, so you don't need to go near the Greenhouse. Save time and effort and provide better temperature conditions for plant growth. NON-ELECTRIC: This opener uses solar thermal induction to open or close Greenhouse vents as the temperature rises or falls. Save energy and your money. PARAMETERS: Maximum fenestration: 45 cm / 18", fully adjustables between 20 - 25 C (68 - 77 F), Maximum fenestration weight: 7 kg / 15 lbs, Adjustables temperature range: 20 - 25/68-77F Greenhouse Window Opener Kit Material: Aluminum Alloy Fully adjustable between 20 - 25 C (68 - 77 F) Maximum window opening: 45cm / 18 inch Maximum opening weight: 7kg/15lb Size: Approx. 38x9.5x5cm / 15.0x3.7x2.0in Package:1 x Automatic Window Opener Kit