Review on 5 Pack SanDisk Micro SDXC 4K UHD Extreme Pro Memory Card (64GB) Compatible with DJI Mavic 2, Pro, Zoom, Air, Spark, Phantom 4 Video Drone Bundle, Including (1) Everything But Stromboli 3.0 TF Card Reader by Rene Putman

These are more expensive microSD cards but well worth it if you shoot 4K video. It seems to be just the right amount to match my drone's battery life. So one card per battery. When I land to change the battery, I slot in a new card and immediately return to it. I would recommend buying a storage box with a quick usage indicator. These things are tiny and if you don't have anything to put them in, you will lose them. And if you don't have a way to mark used and unused, you can mix them up if needed!