The sao truc is a simple instrument consisting of a length of fine bamboo pierced with finger holes, and has long been connected to Vietnamese cultural and spiritual life. Particularly popular in the countryside, it was traditionally played by resting farmers taking a break from working in the fields.

The flute ranges in length from 40 to 55cm, with a diameter of 1.5 to 2cm. At one end there is an oval blowing hole and a soft wooden rush pith used to adjust pitch. 12cm from the blowing hole there are six finger holes at 1cm intervals from each other, as well as a non-covering hole located at the other end of the instrument.

During the 1970s, well-known artists Dinh Tinh and Ngo Nam developed a new version of the sao truc with ten finger holes, allowing performers to extend their register.

The sao truc is now a popular accompaniment to cheo operas as well as a solo and ensemble instrument.