So, it really depends on the specific airport's requirements. Each airport has different rules. For example, when I traveled from Hangzhou Xiaoshan Airport to another location, the airport didn't charge me for bringing my own water; they just checked to make sure it was actually water. When I returned from Urumqi Airport to Xiaoshan, the airport prohibited me from carrying any bottled or unopened water, regardless of whether I had opened it or not. Similarly, regarding my handheld device, whether I could bring it back is a different question. It's best to call the airport beforehand to inquire. When I arrived in Jieyang Airport in Guangdong this year, I checked in and out, and the airport didn't have any issues with my handheld device.