The Saw is a bowed string instrument. The musical sound is produced by rubbing the horsetail hairs that are tied to the bow against the strings to make vibration and pressing fingers on different positions of the strings to produce different pitches.
         The Saw U has seven main component parts.
         1. The neck (Tuan Saw or Kan Saw) is made of several kinds of solid hard wood or ivory in a long cylindrical shape. The upper part from immediately under the tuning pegs up to the top (called Tuan-bon) is made round and decorated at intervals with rings (called Luk Gaew). The tapering lower part is inserted into the sound box.
         2. The tuning pegs (Luk-bid) are made of hard wood or ivory in the cylindrical shape with the cut tips. They are inserted through the upper part of the neck (Tuan Saw) and tied to the two strings called the principal (high pitch) string and the low pitch string. The pitches are tuned by twisting the pegs to adjust the tension of the strings as desired.
         3. The sound box is made of a large oval-shaped coconut shell and cut open at one end so that 2 bulges remain on the upper part of the sound box. The rear of the sound box is carved in an intricate pattern and pierced through for the sound to come out. The front of the sound box is covered with goat skin or calf skin.
         4. Rad-ok is a cord fastened around the strings and the upper part of the neck. It is in the position that the player presses his fingers on the strings while playing the instrument. The Rad-ok is usually made of silk string of the same size as the principal string.
         5. The bridge (Mon—pillow) is placed on the skin covering the sound box to support the 2 strings. It will transfer the vibration to the skin cover and to the sound box. The bridge is usually made of tightly rolled paper, about 2 centimeters wide, and covered with a piece of cloth.
         6. The bow (Kan Chak) is made of the same kind of solid hard wood used to make the neck (Tuan), or solid ivory, in a long slender curved shape. About 250 horsetail hairs or small nylon strings are fastened with proper tension to each end of the bow and set between the principal pitch and low pitch strings.
         7. The strings are made of silk of different sizes. The inner string which is the bigger one is the low pitch string. It is tuned to the ‘So’ pitch. The outer string, which is smaller, is the principal string or the high pitch string, is tuned to the ‘Re’ pitch.
         Apart from being played in the String, Mahori, Pii Pat Mai Nuam and Deuk-Dam-Ban ensembles, the Saw U has a significant function as a solo instrument played at the Hun-Gra-Bok (puppet) performances as well as the Aew-Klao-Saw (singing along with a Saw) performances.