This means that this speaker is sold to North America, and the difference in each region is mainly the voltage difference. For example, AC 1 10V is used in North America, and AC220V is used in China. Of course, if you buy a transformer, you can also use it in our country. Another difference is the difference of safety certification. China generally has to pass CCC, while those exported to other regions have to pass the safety standard certification of that country!