About this item Material: Greenhouse Automatic Window Opener is made of aluminum spray-painted cylinder, aluminum frame looks more lustrous, and rust-proof, is built to last and withstand harsh weather conditions, would guarantees long-lasting performance. Temperature-Sensitive Ventilation: Automatic Window Opener used for greenhouse venting, Auto open and close windows through temperature changes. Operating between 15°C to 25°C (60°F – 77°F), the opener adapts to various weather conditions. Energy-Efficient & Eco-Friendly: The greenhouse window opener does not consume batteries or electrical power needed, which is energy-saving and environmentally friendly. Our automatic window opener will automatically open and shut your greenhouse window to maintain the best growing temperature and preventing your greenhouse from overheating, efficiently regulating your greenhouse’s internal climate. Double Spring Design: Compared with the single spring vent, the double spring greenhouse window opener has stronger thrust force, more solid, and much durable. Lubricate all movable parts with a light oil after fittingeach spring to maintain.(Applypetroleum jelly or grease to the cylinder threadoccasionally) Widely Applicable: You will receive 2pcs of automatic greenhouse vent openers with 3pcs cleaning rags, enough quantity to meet your needs and replacements. These greenhouse accessories are practical and useful tools, which can be widely applied for greenhouse windows and greenhouse vents in higher wind situations, maintaining the nice growing temperature and preventing your greenhouse from overheating