Wikipedia
Triola
The Triola ( listen) is a children's musical instrument, a hand-tuned single tone wind harmonica. The Triola is manufactured by C. A. Seydel Söhne in Klingenthal, Germany.
C. A. Seydel Söhne is the oldest harmonica factory in the world still in existence. The Triola is designed to teach children from the age of 2 and above how to read and play music. It works by simply blowing into the instrument and pressing the coloured keys. The coloured keys correspond with the coloured notes on the music.
It is available in two sizes: With 12 notes from G to D, 26.4 cm in length and with 8 notes (an octave) from Middle C to C, 20.4 cm in length.