Overall vent size: 260mm x 165mm | Screw hole distance: 248mm x 152mm For openings up to 229mm x 152mm (9" x 6") | Airflow when open: 8500sq mm This adjustable aluminum vent is ideal for providing air flow through a building, helping to reduce problems caused by stale air, dampness, smells and condensation Suitable for interior & exterior use. Designed to cover a double brick aperture Central sliding point to open and close giving the user full control of the ventilation required, Weight: 0.23589462034 pounds, Manufacturer: Map