The Helios ETS 125 is a high-performance cross talk attenuator crafted from durable polyurethane foam. It is engineered to reduce acoustic transmission between rooms in central ventilation systems. Designed for use with ducts of nominal diameter 125 mm, it installs effortlessly by inserting into the duct just behind the air valve. This sound damper enhances noise control and provides a quieter indoor environment, ideal for residential and commercial applications.