This is your opportunity to acquire one of the hard-to-find 1.5" diameter
vernier knobs, newly manufactured. While once these were plentiful in radio and
electronics stores of the Sputnik era, they, and the stores that carried them,
have largely vanished. These though, are highly sought after by crystal radio
experimenters and ham radio enthusiasts. Inside diameter 0.255", accepting a
1/4" (6.3mm) shaft, this vernier has a smooth 7:1 reduction ratio, and is
numbered 0-10. Limited supply on hand. Hardware included.