SanDisk Extreme Pro 200MB/s SDXC 256GB: The most powerful SD UHS-I memory card to date, it saves valuable time transferring media files with read speeds of up to 200MB/s thanks to SanDisk QuickFlow technology. For maximum speed, use it with the SanDisk Professional PRO-READER for SD and microSD cards (sold separately). Capture high-resolution, lossless 4K UHD video with write speeds of up to 140MB/s and UHS Speed ​​Class 3 (U3).