What are the differences exactly? Can someone educate me, or point me to a reference that can? I have a Chinese purchased Xperia ZL L35H (No C65**). When I flashed AOKP on it, the model number showed up as C6503, and it worked fine. I flashed a C6502 build on it, which worked fine but the mobile data didn't work. I then flashed a C6503 on it, and soon learned that I had to download a patch by going to Settings/Xperia/Internet settings to get 3G mobile data to work. I'm guessing this would have worked on the C65o2 as well if I would have tried it. So, what exactly is the difference? Is there a substantial risk in trying to flash the wrong one?