Wikipedia
Koudi
The koudi (Chinese: 口笛; pinyin: kǒudí; also spelled kou di) is a very small Chinese flute made from bamboo. It is the smallest flute in Chinese Flute family. Its original shape is from prehistorical instruments made with animal bone, while Koudi is made with wood, bamboo or PVC, which is very distinct with the original shape. It was invented in 1971 by dizi master Yu Xunfa ( 俞逊发, 1946–2006).