Issued by the Ryukyu Islands (琉球郵便) in 1965, this 3-cent stamp commemorates the completion of the Kin (Kinbu) Power Plant, symbolizing post-war industrial growth and electrification across Okinawa. The detailed illustration shows the generating station, cooling structures, and transmission substation, highlighting modern infrastructure development. Its soft green palette and technical architectural style are characteristic of mid-1960s Ryukyuan industrial issues. A desirable topical piece for collectors of energy, engineering, and Okinawa postal history. Popular both mint and used within U.S.-administered Ryukyus period collections.