General description The vhbw conical filter is designed for use in the Zehnder STB 125 ventilation system. This exhaust air filter effectively prevents contamination of ventilation ducts in the exhaust air area while ensuring quiet operation of the exhaust air valves. Technical specifications Filter class: G4 Filter size: DN 125 Diameter: 12.5 cm Length: 18 cm Width: 18 cm Thickness: 0.8 cm Material: synthetic fibre Colour: white Binder-free, thermally bonded Compatibility and accessories Compatible with Zehnder STB 125 Replacement for Zehnder 990320032 Installation Fits on all round exhaust air disc valves with a mounting ring diameter of 12.5 cm (DN 125) Valves are secured into the mounting frame/mounting ring using a quarter turn Usage Designed to prolong the service life of your electronic devices