The Sentinel D‑Box Single Fan 400mm (Stock Ref: SENT400S) is a high-performance demand ventilation solution designed for commercial environments. It supports duct sizes from 100mm to 500mm and delivers airflow between 0.001 and 1.3 m³/s with pressures up to 650 Pa. Equipped with low-energy EC/DC motors and backward curved impellers, this unit provides efficient and reliable airflow management. A lockable isolator ensures safe operation, while the robust Aluzinc construction makes it suitable for both internal and external mounting. Manufactured to BS EN ISO 9001 standards and performance-tested to BS848 Part 1 & 2, the Sentinel D‑Box Single 400mm offers dependable, energy-efficient ventilation for commercial applications.