The Helios ELFBR 200 G4 is an in-line air filter box designed for ventilation systems with circular duct connections. It features spigots on both ends equipped with double lip rubber seals to fit nominal duct sizes precisely. The casing is constructed from galvanised sheet steel, ensuring durability. An access panel secured by a clamp allows for quick and easy filter changes. The filter media consists of synthetic fiber classified as ISO Coarse 70% (G4). It is temperature resistant up to +100°C, fire resistant according to DIN 53438 F1, self-extinguishing, and capable of regeneration 10 to 15 times. This filter offers a dust holding capacity of 122 g/m², supporting effective air filtration and system performance.