This is a harmonica designed by Dana Keller, PhD. It's a Seydel low D in spiral tuning. Dana says the low vibrations help loosen secretions in the airways. And the chord structure of a spiral tuned harp allows harmonious chords without needing to play a single note.
By the way, Pulmonica is a SPAH Silver Sponsor, as are HarmonicaMD (which has another therapeutic harmonica designed by John Schaman, MD), Seydel, and Suzuki USA. =========== Winslow