https://www.theregister.co.uk/2017/08/31/sandisk_microcard/

WDC has the highest-capacity microSDXC card at 400GB – pumping up mobile device storage space – and has launched a natty little iPhone charger that backs up the phone’s data.

The SanDisk Ultra Plus microSDXC UHS-I card comes in a range of capacities, from 16GB through 32, 64, 128, 200, and 256 to 400GB. The read speed is up to 100MB/sec.