The name says it all. As mentioned in several reviews, there are many fake SD cards that have flooded the market and managed to infiltrate multiple marketplaces. I tested mine with the FakeFlashTest tool and it reported they were the correct size but didn't fully load them in non-synthetic settings. That being said, I'm confident enough to say they're legit. Especially when you look at the printing of the cards themselves and the printing of packaging. No house font appears to be used and everything appears to be printed with the correct orientation. As far as I can tell, there are no physical signs of a fake. This, of course, relates to my own experience; All in all I was lucky. I have provided photos of both FFT tests, images of the front and back of the SD cards and the packaging for your reference.
Kingston microSDXC 64GB Class 10, V10, A1, UHS-I U1, R 100MB/s Memory Card, SD Adapter, 1 pc, Black
45 Review
Smartphone Xiaomi Mi 8 Lite 6/128 GB, midnight black
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Silicon Power Elite 64GB microSDXC 2-Pack Memory Card with Adapter for Nintendo Switch and Wyze Cam
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Memory card Samsung microSDXC 256 GB Class 10, V30, A2, UHS-I U3, R 130 MB/s, adapter to SD
50 Review