The Helios ELF-ALB 80/50 F7 is a fully synthetic replacement filter designed for ALB fresh air boxes. It is composed of synthetic filter fleece supported by a durable fiberplast frame, ensuring consistent filtration performance. Tested according to DIN EN ISO 16890 standards, this filter holds an ISO ePM1 50% efficiency rating, corresponding to class F7. It provides reliable air quality maintenance for Helios ventilation systems.