The Klui Gruad is a medium size Klui, which is smaller than the Klu iPiang-aw, and larger than the Klui Lip. The tube is about 40 centimeters long, and 2.2 centimeters wide. Its lowest pitch is one pitch higher than the Klui Piang-aw.
          The Klui Gruad was created to solve the problem when playing the Thai musical instruments in the western ensembles such as in ensemble with a mixture of Thai string instruments and the piano, an ensemble with a mixture of Thai string instruments and the organ, and in applied music ensembles.