SanDisk Extreme PRO microSDXC UHS-I V30 A2 170MB/s 256GB (SDSQXCY-256G-GN6MA) Up to 170/90MB/s read/write speed, video speed C10, U3, V30, A2 Capacity: 256 GB Form Factor: microSDXC Bus Interface: UHS-I Read Speed: up to 170 MB/s (1133X) Write Speed: up to 90 MB/s (600X) Video Speed: C10, U3, V30 App Optimization: A2 SD Adapter: Yes, inclusive At a glance ✓ Transfer faster with read speeds up to 170MB/s ✓ Up to 400GB for more space to catch the thrill ✓ Delivers 4K Ultra HD and Full HD video recording and playback ✓ UHS Speed Class 3 (U3) & Video Speed Class 30 (V30) for 4K UHD video ✓ A2-rated for faster app performance ✓ Built for extreme conditions temperature proof, water proof, shock proof, and x-ray proof3