This is a small musical wind instrument, resembling a tin flute, native to the community of Ressik, on the now-dead planet Kataan.
A space probe launched from Kataan contained the lifetime of memories of Kamin, including the knowledge of how to play ressikan flute. It also contained a single artifact, a ressikan flute.
Jean-Luc Picard is given the memories and the flute, which he treasured.
The flute first appeared in Star trek: The Next Generation, episode number 125 "Inner Light", of season 5 (stardate 45,944.1).