Blauberg 125mm Circular White Ceiling Air Valve Vent Diffuser MVHR Ventilation System Brand new and still in original packaging. Left over from house installation. 11 vents Please see my other listings for more ventilation items, I’m happy to combine postage. 125mm Duct Size: Designed for 125mm ducting systems. Adjustable Airflow: Features a controllable ceiling-mounted grille with locking for this size. Brilliant White Finish: Blends seamlessly with white ceilings. MVHR Compatible: Suitable for Mechanical Ventilation with Heat Recovery systems using 125mm ducting. Extract and Supply: Can be used for both intake and exhaust air in 125mm systems.