
The description says for use with 4K video with read speeds up to 100 MB/s, write speeds up to 80 MB/s. A writing speed of 30 MB/s was specified on the back of the packaging. I put it in my Gopro Hero7 and tried to record a 4K video and got the "Card too slow" error. Obviously these cards had the wrong label. It should read "V30, U3, Class 10, Ai, XC I". But obviously it only delivers up to 30MB/s? Impossible. I'm sending it back to Revain for a refund.

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