I just finished redoing a Yellowjacket -- it's a very fine piece of machinery! And my guess is it cost quite a bit to build. Which may expain this.

When I look through the catalogs, it looks like it was available for one year only. Same with the Super Speed?

The Yellowjacket seems to have been resurrected as the Magnum. No longer direct drive, but with a chain drive. What a shame.

The Tempo King seems to have been in production since sound was invented. Why not? A nice little belt drive pedal.

The YJ was a great design, very thorough, quality build. Slingerland must have lost $$ on it, sadly.