RAZ provides automatic pressure relief/sustaining in supply & extract systems: it stabilizes differential pressure between adjacent zones, protects ductwork and equipment from pressure spikes, and ensures directed airflow. The adjustable opening range of 50–150 Pa allows precise on-site tuning for offices, healthcare and clean areas, and process spaces. The unit is built for long-term operation in general ventilation: a galvanized steel body with low leakage (EN 1751: casing Class C, closed-blade Class 3) and operating temperature 0…+80 °C.