Qin number, Qin number is equivalent to a person's ID number, representing the identity of this piano. You can query the date of manufacture and other related information through the piano number. Kavaj did introduce Japanese technology, which was made in China and tested by the Japanese themselves. This is one of the reasons why Yamaha is expensive and Kavaj is cheap. Kavaj never advertises and returns the remaining advertising fees to consumers, which is the second reason for the preferential price in Kavaj. At present, there are two major Kavaj production bases in China, one is cooperation with Beijing Xinghai, and the other is cooperation with Hubei Yichang Perth Hong Kong.