I was just offered(hard sell) a nib Leupold Mark 4 at about half price, as it seemed to good to be true I checked the Leupold website and they had a warning about counterfeit Mark 4's from China. I've seen quite a few "Trijicon" acogs from China, anything else out there we need to watch for?

Bogus 'Aimpoints' abound on eBay.

George