canon eos r card slots - Product Manual : EOS R6 : Compatible Cards - Canon oyo 888 slot

Recommendation: The Canon EOS R6 has UHS-II SD card slots. To take full advantage of all of the camera’s features, it’s best to use UHS-II SD cards.

Canon expands its R-series mirrorless system with a compact, high-performance EOS R7 APS-C camera! 32MP sensor, R3-based AF system and more! See our Canon R7 preview for all the details!

So, the Canon EOS 5D Mark IV has two memory card slots: 1x CompactFlash memory card slot (UDMA 7 compatible) and 1x SD memory card slot with UHS-I support.