From a local vape shop where I also tried their VTC5, VTC5A and VTC6…

I’m pretty sure their VTC5 and VTC6 are genuine, based on capacity tests and which also has low resistances.

I couldn’t differentiate with anything definitive whether their VTC5A and the VTC5 are the different or the same though (whether their VTC5A is just a rewrap of the VTC5 because they seem to perform almost exactly the same — similar capacity and similar resistance when tested on the MC3000 or other charger with resistance check function, and also seem to perform similarly when used inside flashlights).

Just recently, I noticed they got these VTC5D so I bought a pair to test. The initial above impression is that these VTC5D are slightly higher resistance though (I show the above resistance check picture, but I also tested in another charger, and the VTC5D is very slightly higher IR than the VTC5A; but then again, the analyzing chargers resistance tests may not be that precise…)