The Best Micro SD Cards for Your Galaxy S9 « Android :: Gadget Hacks
How to use micro SD card on Galaxy S9 and S9+? - Galaxy S9 Guides
SanDisk 128GB Ultra Micro SD SDXC UHS-I Class 10 works with Samsung Galaxy S9 Memory Card S9+, S9 Plus (SDSQUAR-128G-GN6MN) with Everything But Stromboli (TM) Card Reader (Class 10 128GB)