The Helios ELFBR 400 G4 is a set of replacement filter mats designed for LFBR in-line air filter boxes. Made from synthetic fiber, these filters are rated ISO Coarse 70% (G4) and are capable of withstanding temperatures up to 100°C. They comply with DIN 53438 F1 fire safety standards, are self-extinguishing, and can be regenerated 10 to 15 times for repeated use. With a dust holding capacity of 122 g/m², this five-piece set offers a dependable and cost-effective filtration solution for maintaining clean airflow in ventilation systems.