When you run out, you can bring it and renew it in a month. You can go on in the same year. Twice a year means that you must use it up within one year. If it expires, it will be invalid. There is no restriction that you can only go twice a year. I often go there. Moreover, you have to pay a bill fee to sign a customs clearance form, which was bought on Taobao. It's only 5 yuan at a time, which is very cheap. Don't buy clearance orders at the gate. Too bad.