Original vintage ad for FISHER RADIO CORPORATION, unbiased MPX-100 Mulfiplex Adapter will work with any brand of FM equipment.  Will convert to FM Stereo operation any FM tuner or receiver ever made.  It also recognizes Multiplex programs automatically with its electronic brain, the Beacon, which lights a signal and switches the equipment automatically from regular to stereo operation.
This unique old one page 1961 high fidelity component equipment trade magazine advertisement would display beautifully matted and framed.  It would make a nice accompaniment to your vintage stereo.