The JAN 12AT7WC Grey Plate. These are 80's military production, with blue and sometimes green lettering, and a (gray plate). The 12AT7 tube type is equivalent to the European ECC81 tube and can be used in any 12AT7 or ECC81 circuit. The 12AT7 tube is commonly used as a phase splitter and also as a reverb driver in many amps.
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