F3, the code name of Shenzhen’s gold jewelry manufacturer. To put it bluntly, Jin Tai Fook does not produce gold jewelry itself. It has registered a copycat trademark imitating Chow Tai Fook, and sells the goods produced by others in small jewelry factories in Shenzhen. When you buy it back, add the word "Jin Tai Fook" on it, and sell it to the outside world, saying that you are the same as Chow Tai Fook.