The Helios FK-ER 150/125 is a specially designed end piece that connects flat ducts measuring 150 x 50 mm to Ø125 mm spiral ducts. Made from robust galvanized steel, it is part of the Helios underfloor duct system, offering a reliable solution for concealed air distribution in domestic buildings. Its compact design supports smooth airflow transitions and helps maintain a clean, low-resistance ventilation layout ideal for new construction projects.