The Helios FM 125 is a flexible sleeve designed to reduce vibration transmission between fans and ductwork. It is intended for use with compatible FR flanges (sold separately) fitted on fan spigots. Supplied in pairs, each sleeve comes with worm screw clamping bands to guarantee a secure fit. Available in sizes ranging from 100 mm to 710 mm, the FM 125 is an effective solution for improving noise and vibration control in ventilation systems.