1. Compatible with Helios, Pluggit, Zehnder exhaust filters: 2. Wide compatibility: Designed for Zehnder, Helios, and Pluggit ventilation valves, ensuring a fit for various ventilation units and systems. 3. quality synthetic material: Made from conical synthetic fleece, our filter ensures air filtration and durability. With a length of 180 mm and DN:125 mm, it provides an ideal fit for filter fleece. 4. filtration efficiency: The G4 filter, with a thickness of approximately 8 mm, delivers professional air filtration, effectively capturing dust and impurities. Its breakresistant design ensures longlasting protection for the fan. 5. Safe and energyefficient: Featuring cleanly treated seams and maximum airtightness, our filters prevent air leakage, ensuring energy efficiency and minimal noise from the ventilation system.