When youre shooting where the action is, the CFexpress Card Type B unleashes the RAW performance of your gear. With read speeds up to 1400MB/s and write speeds up to 1700MB/s, [512GB only; 128GB-256GB = 1700MB/s read / 1200 MB/s write; 64GB = 1500 MB/s read / 800MB/s write] youll get low latency during high-speed recording and an enhanced workflow efficiency thats far beyond anything existing SanDisk cards deliver. | Up to 1700MB/s read speed; up to 1400MB/s write speed. Based on internal testing; performance may be lower depending upon host device, usage conditions, and other factors. 1MB=1, 000, 000 bytes.