Shuangyu, double-reed gas-sounding instrument. Also known as "Double Poetry". Among the nine tricks in the Sui Dynasty and the ten tricks in the Tang Dynasty, it was only used for Anguo tricks. It is bundled with two same-duty teapots. Today, the two-pipe and double-chambered teapots in the Yanbian Korean Autonomous Prefecture in Jilin Province and the Korean areas in Liaoning, Jilin and Heilongjiang are all belonging to his legacy system.

The tube body is made of bamboo, the length of the tube is 18 cm to 22 cm, and the inner diameter of the tail end is 0.6 cm. The tube body has eight sound holes (seven in the front and one in the back), and there is a reed oboe on the top of each tube. The whistle is 4.5 cm long. The upper and lower ends of the bamboo tube are inlaid with copper hoops. The head and tail of the two tubes are respectively tied with silk strings or firmly connected with metal sheets.