One octave, 8 notes diatonic in C major. The little instrument sounds like a harmonica. Length: 33cm. Maybe this unique French fantasy items was inspired by the Louis Jaulin Harmonicor which had similar valves with reeds - patented in 1861.
I was sent these pictures of instruments that 'Chapi Chapo & les petites musiques de pluie' use. The music is very nice, ghostly cinematic sound - like a cross between Tunng and Yann Tiersann. I thoroughly recommend checking out their myspace site.