Tested and certified to work seamlessly with Chromebooks Instantly add up to 64GB of storage to carry your photos, videos, and other files (1GB=1,000,000,000 bytes. Actual user storage less.) Up to 140MB/s transfer speeds let you move photos and files fast (Up to 140MB/s read speed, engineered with proprietary technology to reach speeds beyond UHS-I 104MB/s, requires compatible devices capable of reaching such speed. Based on internal testing; performance may be lower depending on host device, interface, usage conditions and other factors. 1MB=1,000,000 bytes.) Load Android apps faster with A1-rated performance (A1 performance is 1500 read IOPS, 500 write IOPS. Based on internal testing. Results may vary based on host device, app type and other factors.) Class 10 for Full HD video playback – watch right from the card (Full HD (1920x1080) video support may vary based upon host device, file attributes, and other factors. See official SanDisk website.)