Did what was needed. My c3 is working again. Tried to see if I could store files from my OSMO 4 though and wasn’t reading in it. But only thing I know is it looks like it should fit. Not a computer scientist here but thanks to the Facebook guy and customer service got my c3 running again.
MicroSD Card for Camera 64GB 128GB UHS-I U3 for HD/FHD/4K Video Recording