Ricoh
Well-known
The SM that came with the camera is 3.3V - think it might be labelled 3V, actually. I’m using a ‘fairly’ modern Hama 35 in 1 reader that supports this particular card. I recollect reading that the card has a cut out to differentiate 5V and 3.3V. Put it this way, I’ve had the card in the Hama several times and it still operates in the camera. There’s a warning that 5V will irreparably damage 3.3V cards hence the cut out to stop loading inappropriately.