- The clever way 2-pack G4 / F7 filter for your ventilation unit for clean, allergy-friendly indoor air Replacement for your current air filters Tool-free filter replacement All compatibility and technical details can be found below These replacement filters quickly restore your ventilation unit to full functionality. The pre-filter removes coarse dust, hair, insects, sand, and other large particles from the incoming air. The pollen filter provides additional protection against fine dust and pollen. Thanks to these filters, pollen and dust particles from outdoor air are prevented from entering the ventilation system. The filters are easy to install into the unit’s slide-in slots without tools. To maintain optimal performance of your ventilation system, filters should be replaced regularly. This filter set allows upgrading your ventilation unit to pollen filter class F7 without installing an external pollen filter housing. NOTE: Airflow direction is marked on the filter elements. Package includes: 2 x Filters (G4 / F7) Technical specifications: Dimensions per filter (L x W x H): approx. 50 x 17 x 1 cm Filter class: F7 (red pollen filter) / G4 (black pre-filter) Type: Pollen filter / Pre-filter Material: Synthetic fiber / Plastic Color: Black / White / Red Compatible with the following models (use Ctrl + F or Cmd + F to search for your model): Zehnder ComfoAir 350, 550, 300 Standard, 375 Standard, Zehnder ComfoD 300, 350, 450, 550, Paul Santos 370, 570, Wernig G90-380, G90-500, G90-550, Wernig ComfoAir 350, 550, Aeris 350, 450, 550, R+F ComfoAir 450, R+F Optiline KWL 350, Sanibel ComfoAir 350 Replaces the following original accessories: Zehn