Hmm, people are making fun of this question but I think it is legit.
My parents used to bring me one or two watches from Shenzhen from time to time. The thing is that it is actually the other way around. Custom officers may think it is a real one so they can charge you import fee.
Once my parents brought me a AAA Sea Dweller. My mom told me that they spend some time inspecting it and that they weren't sure. After my mom told them that a Gen would never be this rough blabla (my mom thinks she can feel reps...) they let it go.
See, because of their (custom) unawareness it can be more expensive than expected. I simply wouldn't risk it or having/knowing proof that it is a rep.