The Helios FR 400 is a robust flange specifically designed to connect circular flanged fans with round duct systems. Constructed from galvanized steel, it features hole drilling and diameter alignment compatible with standard Helios fans. The integrated spigot supports both flexible connectors and direct duct fittings. As part of a range covering sizes from 180 mm to 710 mm, the FR 400 ensures dependable integration into various ventilation applications.