I was replacing a couple of customer supplied chains on 2 bikes that I was tuning up at the bike shop where I work. I've come across this issue a few times now since the pandemic created so many issues with product availability, many times with Shimano parts, but we're seeing lots of counterfeit parts purchased off Amazon. In this situation, after inspecting the supplied chains, I made a quick video comparing one of the fake supplied chains to a genuine Shimano chains. Hopefully the video will be helpful to someone who purchased a chain on Amazon or eBay at a really good price to determine if it's real or not. Most home bike mechanics are always looking for ways to save money, but this is one area that in my opinion is just not worth it.