The khlui is probably the first wind instrument which the Thai devised themselves although the shape of the instrument is very similar to Indian flute. The khluiis also similar to the Japanese flute. In the old days, the khlui was made of a long length of one variety of bamboo, cut so that there would be a "node 1" from the lower end. This node, however, was pierced so that there was an open shaft throughout the entire length of the instrument. This is still the basic model used today. After cutting and hollowing, the instrument is carefully dried out over a fire.
The khlui is very similar to the Cambodian khloy, though there are differences in tuning between the two instruments.
It comes in three sizes: khlui lib (small), khlui piang aw ( medium), and khlui yai (large).
The khlui once had a buzzing membrane similar to the Chinese di mo, but this is not used today.