The single most important thing to know before you pack: mainland China and Hong Kong do not use the same plug type. If you bring one adapter assuming all of “China” is the same, you will be hunting for a hardware store in Kowloon at 11pm. This is not legal advice — consult a licensed attorney if you have questions about electrical compliance in your destination country. But for travel purposes, the practical rule is simple: mainland China runs on 220V at 50Hz with Type A and Type I sockets. Hong Kong runs on 220V at 50Hz with Type G…