What determines whether you should use a Sandisk A1 or A2 micro SD card for more storage on Android phones? Is the A1 better if not storing photos/videos? - Quora
All about SanDisk's microSD cards with the new A1 speed class - HardwareZone.com.sg
A1 VS A2 SD Card: Compare Them and Make a Wise Choice - MiniTool Partition Wizard
Amazon.com: SanDisk Extreme PRO microSDXC Memory Card Plus SD Adapter up to 100 MB/s, Class 10, U3, V30, A1 - 64 GB : Electronics