Designed for mirrorless and DSLR cameras, the 256GB Professional 1066x UHS-I SDXC Memory Card (2-Pack) from Lexar lets you quickly capture and transfer high-quality photos, including Full HD and UHD 4K video with read speeds of up to 160 MB/s and write speeds of up to 120 MB/s. All of this allows you to dramatically accelerate your workflow. These cards have also been built with a capacity of 256GB per card and the V30 Video Speed Class rating, which guarantees minimum write speeds of at least 30 MB/s. To help increase durability, Lexar made this card resistant to water, shock, vibration, x-rays, and temperature extremes. A built-in write protect switch will help guard your data from accidental erasures.