Mr. Yu is a single-reed gas-sounding instrument of the Jingpo and De'ang peoples. In Jingpo language, "筚" is a general term for air-sounding musical instruments, and "general" means double, which means a pair of air-sounding musical instruments with parallel pipes. Folks have the same style but different specifications.

Zhanxi, the one among the generals. It got its name because this musical instrument first came from Zhanxi Township, Yingjiang County. The tube body is made of bamboo and consists of main and auxiliary tubes, and the shape is the same as that of Ruizuo.

The length of the main pipe is 27 cm, the inner diameter of the tail end is 1 cm, and the first end is left with a joint. There is a square blow hole on the wall of the tube under the section, and a sharp triangular copper reed is sealed. There are six (the first five) in the middle and lower part of the tube body The latter one) round press sound hole, the hole distance varies. The length of the auxiliary tube is 21 cm, the inner diameter of the tail end is 0.6 cm, and the head end is opened with a blow hole, inlaid with a reed, and no sound hole is opened.

The auxiliary pipes are arranged side by side on the left side of the main pipe, and the side of the pipe wall adjacent to the main pipe extends down to be flush with the tail end of the main pipe, and the two pipes are tied together with bamboo strips at both ends. At the end of the head of Zhanxi, a small gourd with both ends cut off is often placed horizontally as a sound resonance tube. From a distance, it looks like a pipe.