With swinging coil antenna coupling. In oak cabinet and ebonite control panel with a number of connections, two plug-in tuning coil holders and a tuning capacitor with Bakelite knob and silver plated metal scale. Can be used to increase the selectivity of a receiver. The tuning condenser is by Nutmeg, Velthuisen represented this company in The Netherlands. The device could also be used as a refection filter (wave trap).