I recently made a bulk purchase of Gillette Fusion Power blades and was surprised at how poorly they shaved, how they fit and how they aged (after being exposed to water.)  Upon careful inspection and a comparison to a package of genuine blades purchased at the local chain drugstore, I realized I had, in fact, purchased counterfeit blades!  The old adage, "if it seems too good to be true" still applies, most of the time, so I should have been suspect simply from the price.  Nevertheless, there are simple ways to identify (at least at this time) genuine Fusion Power blades from the counterfeit fakes.

1.  The easiest way to identify a genuine blade is to look for the serial number when the base of the blade is flipped up to expose the hinge mechanism:


notice the numbers/letters on either side of the hinge on the blade above


the counterfeit blade has no markings (be aware in the future all blades may have a marking, but that on genuine blades every blade's serial number will be different)

2.  On my blades another easy way to tell the difference is the molding of the side grey plastic piece:


the genuine blade is on the left and the grey plastic is smooth... the fake is on the right and has a noticeable "dimple" from the molding/injection machine.  If you look closely you can also see that on the genuine blade the locking tabs (silver) are pressed down and in place while on the fake the tabs are up in the air (and easy to press with your finger!)

3.  Another obvious difference (at least on my blade) is the construction of the orange 'rubber' skin tensioner.  On the real blade (left) there is a dimple while on the fake blade (right) there is a slot:



4.  If you look closely at where the handle attaches to the blade you can see another significant difference.  On the genuine blade the molding for the alignment is sharp and has a number of different components (first photo) while on the counterfeit blade the molding is soft/sloppy (and, as a result, the handle doesn't fit properly)




5.  And finally (eech!), while the genuine lubrication strip seems to dissolve smoothly, the counterfeit blade's strip starts breaking down almost immediately, creating a mess along the top of the blade




I hope this helps someone else avoid buying a fake blade and slicing up their skin!