We offer the best selection of quality made solar vent openers in the USA. All window openers open and close automatically based on air temperature and offer adjustable temperature settings. These are great solutions for automating side and roof vent windows on greenhouse kits and cold frames. Want more information about how they work and/or which vent opener is best for your application? Visit our Adding Automatic Vent Openers to your Greenhouse article. Dealer inquiries are welcome.