Western Digital announced the world’s first SanDisk 4TB microSDUC UHS-I and SanDisk 8TB SDUC UHS-I memory cards at the Future of Memory and Storage Conference. SDUC is a new standard above SDXC with many similarities with SDXC like supporting exFAT and SD Express mode E150, E300, E450, E600, but it represents cards starting at 2TB and ranging up to 128TB while SDXC cards range from 32GB to 2TB.
Sandisk cards can be found at B&H Photo and Amazon
via Photorumors