I have been buying Gillette Fusion blades from eBay for a few years now. The last couple of times I ordered Gillette5 blades. They are of the same design without the trim blade on the back side. I bought the 5's twice and the 2nd batch said "Fusion" on their plastic holder. Long story short they were counterfeit.
All the Fusion blades were genuine. I just ordered some more Fusion 5's. I have come to learn recently that they are one of the top ten
shop lifted items that are sold one eBay.
BTW, the counterfeit Gillette blades worked just fine, I would never have known if I hadn't checked them.
It's easy to tell them apart.