Save time with card offload speeds of up to 170MB/s powered by SanDisk QuickFlow Technology Pair with the SanDisk Professional PRO-READER SD and microSD to achieve maximum speeds (sold separately) Perfect for shooting 4K UHD video and sequential burst mode photography (Full HD (1920x1080) and 4K UHD (3840 x 2160) video support may vary based upon host device, file attributes and other factors. See HD page on SanDisk site.) Capture uninterrupted video with UHS Speed Class 3 (U3) and Video Speed Class 30 (V30)