With incredible speed, the officially licensed SanDisk microSDXC card for the Nintendo Switch lets you add up to [64/128/256GB] of space for your system. Spend less time waiting and more time gaming with read and write speeds of up to 100MB/s and 90MB/s respectively. Perfect for keeping your favorite games in one place. Backed by a lifetime limited warranty, so you’re ready for the long haul. 1GB=1,000,000,000 bytes. Actual user storage less. (1)128-256GB: Up to 100MB/s read speed; Up to 90MB/s write speed. 64GB: Up to 100MB/s read speed; Up to 60MB/s write speed. Based on internal testing; performance may be lower depending upon host device interface, usage conditions and other factors. 1MB = 1,000,000 bytes.