Dimensions and technical details Disc valve for air supply and air extraction systems Various size options available Housing colour: white (plastic)  Twistable centre piece for continously adjustable regulation of the airflow, including close-fitting gasket ring Easy to install on ducts, in suspended ceilings, on walls Includes clip springs and mounting flange with lock ring Application in supply and exhaust ventilation systems, air conditioning systems Model D (mm) D1 (mm) D2 (mm) H (mm) H1 (mm) Air pass (m²) A 80 VRF 80 90 132 58 18 0...0.002 A 100 VRF 100 90 148 58 28 0...0.006 A 125 VRF 125 110 166 58 20 0...0.008 A 150 VRF 150 128 200 58 20 0...0.009 A 200 VRF 200 128 246 58 20 0.001...0.008