Originally Posted by
moondog
You can't order ahead. You might pay a bit of premium to get a SIM at PVG (v. In town), but this is probably worth it. Go with Unicom unless you are certain your phone can do 4g on China Mobile (less of an issue these days, but I've met many people who end up buying a second SIM).
Switching topics, I strongly encourage you to join our WeChat group. Think of it as a free concierge service

What is the WeChat group name? I haven't installed wechat yet since I was going to do it with my Chinese number and try to link my american credit cards to it. My phone is the samsung S8 galaxy not sure if that will run 4G with china mobile.