SanDisk® Global Customer Support (US)

SanDisk has introduced the MicroSD A2 cards to the market. The A2 cards have extreme speeds for fast transfer, app performance and 4K UHD video recording.
Performance of the A2 cards read speed is up to 170 MB/s and write speed up to 90 MB/s.

SanDisk's latest proprietary technology has enabled performance beyond UHS-I 104 MB/s limitations.

The A2 cards are compatible with our SanDisk Mobilemate USB 3.0 Micro SD card reader (SDDR-B531) to achieve host device speeds up to 170 MB/s.
https://www.sandisk.com/home/memory-cards/memory-card-readers/mobile-mate-3

IOPS is a performance measurement used to characterize computer storage and devices.

A2 performance is 4000 read IOPS, 2000 write IOPS.
A1 performance is 1500 read IOPS, 500 write IOPS.

Please note:  In order to achieve the best performance you'll need an A2 compatible host device. Results may vary based on host device, app type and other factors.