It's called a bamboos.
Air Bamboo, the ancient name of Hu knock, empty bells, empty zheng, commonly known as buzzing, ringing bells, turn bells, the old cow, boring gourd, wind gourd, ringing gourd, Tian Lei Gong Gong, belongs to the Han Chinese folk traditional toys.
Typical hollow bamboo has a single round and double rounds of points, double rounds of hollow bamboo shaped like a drum, made of bamboo or wood, the two ends of the two flattened round wheels, hollow inside the wheel, the wheel dug four or five small holes, holes placed in the bamboo flute, the two wheels are connected to the shaft; a single round of hollow bamboo shaped like a gyroscope, a side with a wheel. Because of its wheel hollow and bamboo flute, so the name "hollow bamboo".
Expanded information: Development History Air Bamboo has a long history in China. According to the evidence, the earliest is the evolution of the Han folk games "gyro". Gyro is a toy that appeared in ancient times, in the Neolithic Hemudu culture site and Changzhou Weidun site, a wooden gyro was unearthed, and Shanxi Xiaxian Xiyin village site unearthed a ceramic gyro. By the Qing Dynasty, the way of shaking the aerial bamboo gradually matured. The Qing Dynasty was a heyday for the development of jitterbug. Not only the theater equipment is simple, easy to learn, and action patterns, techniques, fascinating, popular. At the same time, the crowd of people involved in shaking bamboo constantly expanding, from children to the royal court nobles, merchants and ordinary people. As a result, jitterbugs were widely practiced in the Qing Dynasty and continue to be practiced to this day. Baidu Encyclopedia - Bamboo Shaking