Mechanical VR1 Volume Flow Controllers are suitable for constant air flow applications. Maintenance-free VR1 Volume Flow Controllers can be used in the both fresh air and exhaust air ventilation systems. They can be installed at any angles. VR1 Volume Flow Controllers with the circular casing can be supplied in the different sizes from DIN80 to DIN315. They contain galvanized steel control mechanism. The regulating device with the rotary pointer, scale and lock adjusts air flow rate. They can be used for the air flow rates from 50m³/h to 3100m³/h and the pressure values from 50 Pa to 1000 Pa. Air flow rate is regulated manually or by an actuator optionally. VR1 Volume Flow Controllers provide high accuracy air flow with the deviation from %5 to %10 from the desired air flow value at the variable pressures. VR1 Volume Flow Controllers have an Environmental Product Declaration and Hygiene Certificate.