An item designed to suppress undesired (interfering) frequencies and have a minimal effect on the desired frequencies when inserted in an electrical power circuit. Excludes items which consist of a single capacitor, inductor, resistor, or devices consisting of only two or more circuit elements of the same basic name. Excludes filter, low pass and suppressor, ignition interference. For items designed to be inserted in a line which is primarily intended to carry high frequency waves modulated with signals, such as antenna lead-in, see filter, band suppression and filter, band pass. See also limiter, electrical noise.