Automatic Roof Vent Opener Solar Heat Automatic Greenhouse Window Opener Dual Spring Greenhouse Accessories Greenhouse Opener Replacement Greenhouse Vent Opener for Ventilation(Up to 30lbs)

Our automatic roof vent opener is made of aluminium alloy material,sturdy and strong,reusable,not easy to break or rust,which can be used for a long time. The dual spring greenhouse opener adopts double spring design,improves the low bearing capacity of the single-spring window opener,the thrust is larger,more durable The solar heat automatic greenhouse window opener does not require batteries or electricity,the opener will remain open when the temperature up to 25°C,will close when drops to 18°C. The replacement greenhouse vent opener with double spring,the maximum bearing force up to 15kgs/33lbs,which can not only be used in lightweight aluminum alloy windows,but also used on wooden windows. This greenhouse is ideal for greenhouse windows and greenhouse vents in higher wind situations,maintaining the nice growing temperature and preventing your greenhouse from overheating.