Up to 60MB/s write speeds for fast shooting (Based on internal testing; performance may be lower depending upon host device interface, usage conditions and other factors. 1MB=1,000,000 bytes.) Up to 100MB/s read speeds to save time transferring high-res images and 4K UHD videos (Based on internal testing; performance may be lower depending upon host device interface, usage conditions and other factors. 1MB=1,000,000 bytes.) Capture stunning 4K and 5K UHD video (Compatible device required. Full HD (1920×1080), 4K UHD (3840 x 2160), and 5K UHD (5120 X 2880) support may vary based upon host device, file attributes and other factors. See HD page on SanDisk site.)