There is one on ebay, seller had a couple others and sold them. It is rarer than his tubes or Fritionwood, more on the scarcity of the Spanish Dagger or Wingwood trumpets...I love all and have all of them, several in different 'variants.' Gary Harms from Missouri was the box manufacturer (verified by Ms Sally, Kenny's wife), and Kenny 'tuned' the box. In Kenny's advertising he called it the 'H-box' or 'Harmful box' which is acknowledging Mr Harms. The very few I know of that sold went for over $200.