Power Line Filters are designed to attenuate and control electrical interference on power lines. They can be used to protect audio equipment, medical devices, or other sensitive equipment from power line noise or other signal disturbances. Power Line Filters work by allowing signals of a desired frequency to pass through while inhibiting all others. They usually consist of an inductor or inductors and capacitors arranged in a pi-type or other configuration, depending on the operating frequency and level of attenuation required.