This series of filters are designed to attenuate frequencies outside a narrow pass-band in the FM frequency range. The band-pass filters consist of two magnetic coupled coaxial resonators with adjustable coupling and input/output coupling loops. The power rating of these filters depends on the dimensions of the filter and the shape of the amplitude/frequency profile. A range of filters are available in design with 2 or 3 cavities to cover the power range from 300 W to 20 kW.

Beryllium bronze is used for spring materials, giving the tuning section a life-time guarantee.

All filters are factory tuned to specified frequency. They are also retunable on whole frequency band.