The Helios ELF-ELSD is a set of replacement filter mats designed for ELS‑V and ELS EC fan inserts. Made from regenerable synthetic fibres, these filters are classified as ISO Coarse 30% and are suitable for repeated use. They are dishwasher-safe for convenient cleaning and long-term performance. Each set includes two permanent filters, providing an efficient and sustainable solution for maintaining air quality in Helios ventilation systems.