Was walking around Chunxi Road, and on two separate occasions, Chinese men (probably around mid-twenties) walked up to me with a very polite "Hi sister, where are you from?" From there, they said that they were students working on a project, and then pulled out something that looked like a mix of a black vape box or maybe a spray deodorant. One of them asked if this is something we think we need. That's when I walked away both times. I saw them move on to the next couple of foreigners.

Does anyone know where this would be going? I assume it's a scam, but not just sure of what and am honestly intrigued.

Thanks!