Very unusual 1-3/8” button consists of a glazed porcelain disk with a smooth glossy front, and unglazed back in a pattern of tiny dots and with the original glued on bar pin. Front shows full figure Betty at 1930s style microphone marked twice with the radio station call letters “KPFA.” Surrounding text reads “Listener Sponsored KPFA-FM 94.” This was the first listener supported non-commercial radio station in the United States. This avant garde station named Pacifica first went on the air in Berkeley California in 1949. It was controversial from the beginning and attracted interference from the government. Likely this piece was issued during the 1980s when Betty was enjoying a nostalgic revival. The piece was probably used as a station fundraiser. Only example we’ve seen. Mint.