Conical G4 Synthetic Filter Sleeve — Compatible with Helios, Pluggit, Zehnder Key benefits — why you need this filter Reliable particle removal: G4 filter class and conical synthetic fleece provide consistent primary filtration to protect fans, ducts and indoor air quality. Exact fit reduces leaks and noise: Precise dimensions and treated seams prevent air bypass, improving energy efficiency and reducing operational noise. Durable and low-maintenance: Robust construction and break-resistant design withstand handling and routine replacement without damage. Features and specifications Compatibility: Designed for ventilation valves and filter housings from Helios, Pluggit and Zehnder for seamless replacement and integration. Material: High-quality conical synthetic fleece delivers stable filtration performance and handling stability. Filtration grade: G4 (coarse filtration) for effective capture of large dust and particles. Thickness: Approximately 8 mm for the filter media. Size: Length 180 mm, nominal diameter DN 125 mm — precise sizing for a snug, secure fit. Seams and airtightness: Seams are treated to maximize airtightness and prevent air leakage from the filter insert. Quality control: Each filter is individually tested to ensure consistent performance and protection for your ventilation device. Performance outcomes Improved system efficiency: Tight fit and sealed seams reduce unfiltered air bypass, supporting lower energy consumption. Lower noise: Proper sealing and correct fit reduce turbulence and associated operating noise. Extended equipment life: Effective pre-filtration helps keep fans and ductwork cleaner, reducing maintenance frequency. Typical applications Residential mechanical ventilation units using Helios, Pluggit or Zehnder valves — routine replacement to maintain indoor air quality. Office or commercial ventilation systems where G4 pre-filtration protects downstream filters and equipment. Renovation or maintenance projects requiring precise replacement filter sleeves (180 mm length, DN 125 mm) to restore original performance. Quality assurance Each filter is tested for fit and filtration performance to ensure reliable operation and protection of your ventilation system.