Designed for microSD devices such as smartphones, interchangeable-lens cameras, drones, or GoPro action cameras that can capture Full HD, 3D, and 4K video, as well as raw and burst photography, the Sandisk 256GB Extreme UHS-I microSDXC Memory Card with SD Adapter has a capacity of 256GB, is compatible with the UHS-I bus, and features a speed class rating of V30, which s 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 s minimum write speeds of 30 MB/s. Read speeds are supported up to 160 MB/s and write speeds max out at 90 MB/s.