...The best way to make sure of this is a fairly new brand class10 SD card that is FAT32 formatted... ...and counterfeit SD cards that say "class10" but are not are a risk..
Aah, yes indeed, Arne...
Sorry folks, but I forgot to mention our (ahem) "old friends", the fakers ...and also that some of their "marketing associates" have been known to re-label and re-pack discarded portable media for resale as "new" (and supposedly "bargain-priced") stock, alongside other "discounted" items that they've acquired in the same nefarious ways.
(Stuff like IEC power cables and batteries. Not just "stuff", but "pre-stuffed". )
Half a second's work, with whatever destructive implement gives us the most satisfaction , prior to the depositing of our old media for recycling, is a great way to both prevent that practice and guarantee the confidentiality of whatever intellectual property we may have (inadvertently) left on them.
I also hold to my firm belief that the cost of genuine, high-performance "key ring" USB drives and SD cards from reputable outlets is truly minimal, especially when compared with the value of the emotional (and quite possibly also financial) investment in "lost" data ...and that a "format" prior to use, (preferably carried out by the recording device itself) is an equally great way to not only pre-detect new media that just might be faulty, but also to avoid seeing those dreaded read/write "error" symptoms later.
Also, (at grave risk of telling folk what they already know) never forget that "data is data is data", so our disciplines of the clear identification and "back-up" transfer of our M20d multi-track files (whether to "the cloud" or any other drive/s or media) can be just as much a real "lifesaver" with audio as it undoubtedly is for our vital personal information.