Overview Designed for SD devices that can capture Full HD, 3D, & 4K video, as well as raw & burst photography, the 64GB Professional 667x UHS-I SDXC Memory Card from Lexar has a capacity of 64GB per card, which will allow you to shoot for extended periods of time while changing cards less frequently. It is compatible with the UHS-I bus & features a speed class rating of V30, which guarantees minimum write speeds of 30 MB/s. If your device does not support the V30 standard, this card also supports the U3 standard, which also guarantees minimum write speeds of 30 MB/s. Read speeds are supported up to 100 MB/s, & if your device does not support U3, this card is compatible with the U1 & Class 10 standards, each of which guarantees minimum write speeds of 10 MB/s. To help safeguard your content, there is a built-in write protect switch. High-speed, Class 10, UHS Speed Class 3 (U3), & Video Speed Class 30 (V30) performance leverages UHS-I technology for read speeds of up to 100 MB/s (667x) & Enjoy shooting longer & changing cards less frequently, thanks to a storage capacity of 64GB