AC 608 Radio tube in original box. Silvered at top, bakelite mount. Sticker on bulb says "To be used in detector position only". Marathon AC 608 Radio tube in original box, 4 prongs. Silvered at top, bakelite mount. Sticker on bulb says "To be used in detector position only". Two small pins at either side. Box has flaps at either side, orange and blue coloured.
