Condition: NOS - Valve radio tuning indicator / fluorescent magic eye made by Valvo, Hamburg-Germany with "MiniWatt" print. The EM87 / 6HU6 has a fluoresence / fosfor layer on the inside of the glass that can also be used as level meter as you find in Fatman iTube or McIntosh MR-73/74 tube tuner. Production date: 1967. Equivalents: EM840, 6FG6, 6HU6, CV10407, CV5434, 6E2. Keywords: magische band, tuning indicator, magic eye, magische augen, magische baender, magischesauge, indicator tube, afstemogen, afstemindicator, magische ogen, oeil magique, cat eye, magischer Fächer.