I accidentally a few years ago bought an SD card that has a U with a 1 inside the card. I like all of us use U 3. What happens with a 1 INSIDE THE U besides a bad quality I presume.
UHS speed class is about minimum write speed. U1 is good for full HD video and may work for 4K video but you cannot be sure. U3 is capable for 4K and 8K video. See a comparison table here: SD card - Wikipedia
I accidentally a few years ago bought an SD card that has a U with a 1 inside the card. I like all of us use U 3. What happens with a 1 INSIDE THE U besides a bad quality I presume.