The khlui is probably the first wind instrument which the Thai devised themselves, although the shape of the instrument is very similar to that of the mu-ra-li of India, which is used to play music in worship of Krishna, one of the Hindu gods.
The Khlui is similar to a Japanese flute called the Shaku-hachi. The Japanese Shaku-hachi and the Thai Khlui are played vertically like the western oboe and clarinet.
The Khlui is made of hardwood, such as Mai Ching Chan or Mai Ma-glua (black color).After cutting and hollowing, the instrument is carefully dried out over a fire.On the front side ,seven small round holes are made in a row over which the fingers sit,opening and closing the holes to change the pitch of the sound.No reed of any kind is used.
The mouthpiece consists of a piece of wood inserted into the opening on the end.Near the opening on the underside is a rectangular hole cut diagonally and slanting in towards the inside of the tube.The Klui must have this cut in order to produce sound.Another round thumbhole similar to the finger holes can be found less than half way down the shaft on the underside.
Above the thumb hole ,but on the right side of the instrument as it is held in playing position there is another round hole called "the membrane hole",covered by thin tissue paper. At the lower end of the body are four more holes made in pairs at right angles to each other.A cord or ribbon is put through the holes going from right to left by which the instrument can be hung up or held by hand.All in the klui has fourteen holes.