A 2TB microSD card fulfils the SD Association's maximum theoretical storage capacity for the microSDXC format, but up to now no manufacturer has been able to produce an actual working 2TB card. Kioxia's attempt is a UHS-I card, so won't be the fastest performer, but the highest capacity SD and microSD cards rarely set any speed records.

The SD Association approved the SDXC spec back in January 2009, which supported memory cards up to 2TB. Granted, that was a theoretical maximum at the time. It took the industry a whole 10 years (!!!) to actually bring 1TB microSD cards to the market and 2TB microSD cards have simply never materialized.