Automatically opens and closes the roof vent/window when temperature changes. The opener has a metal cylinder containing a mineral which expands when heated. This pushes a piston that opens the vent. As the temperature cools, the mineral shrinks and a spring closes the vent and resets the piston. The opening and closing of the vent is gradual allowing just the right amount of air flow for cooling.
Trustpilot
1 day ago
2 weeks ago
