JAN5727/2D21W

Premium military-spec miniature 7-pin gas-filled cold-cathode tetrode thyratron tube designed to handle high peak currents as an electronic switch or pulse relay trigger. Equivalents: 2D21, 2D21W, 5727, EN91. Real-Life Examples: Vintage jukebox control reject selectors, early digital instrumentation stepping arrays, industrial automated timing devices.