The SanDisk Extreme PRO UHS-I V30 memory card (512 GB, microSDXC, U3, UHS-I) should fit in the DJI Mini 4K as the drone supports microSDXC cards. However, the maximum storage capacity of the DJI Mini 4K is limited to 256 GB, which means that the 512 GB card is technically compatible, but the drone may not be able to utilise the full capacity.