The Leica M 10-R features a single memory card slot that supports SD/SDHC/SDXC UHS-I cards.
SD cards up to 2GB, SDHC cards up to 32GB and SDXC cards up to 512GB are the maximum sizes supported.
UHS-II cards will work but do not offer any speed benefits in-camera, however you will find it faster to copy files off your cards when using a UHS-II card reader.