For the same car, many manufacturers will produce navigators for it, such as Gefei, Huayang, Kaster and Lushi. Different brands and models of navigators have different ports and baud rates. Therefore, it is best to choose the upgrade program according to the version number of the navigation software that comes with the original factory. For example, if the original main program is C 1228, you need to select the main program accordingly.
Just choose the one that suits you!