Patriot EP Pro 64GB Micro SDXC Card U3, UHS-I, Class-10, 90MB/sec Read and 80MB/sec Write for 4K Recording Speeds up to 90MB/sec read and up to 80MB/sec write. U3 - for 4K ultra high definition recording, 30MB/s minimum write speed UHS-I (Ultra High Speed) Compliant Write protection switch to avoid accidental data deletion