Eaton Oscillator, Wireless Speciality Apparatus. The label states, "Type-Triode C, Serial # 192, Wireless Speciality Apparatus. Eaton oscillator's could be used as a part of a radio receiver or in the laboratory to generate RF signals. Used in a radio, the external circuit is etched in white on the panel and the internal circuit is etched in red. It cost $14.90 in 1919.