The Sentinel D‑Box Twin Fan 250mm (Stock Ref: SENT250T) is a commercial demand ventilation unit built for reliable performance. Suitable for duct diameters from 100mm to 500mm, it delivers airflow ranging from 0.001 to 1.3 m³/s and pressure levels up to 650 Pa. Featuring energy-saving EC/DC motors and a lockable isolator, the fan ensures safe and efficient operation. Its robust Aluzinc construction allows installation indoors or outdoors. Manufactured under BS EN ISO 9001 standards and performance-tested to BS848 Part 1 & 2, this fan provides dependable and energy-conscious ventilation for various commercial environments.