The 64GB microSDXC Memory Card Premium 300x Class 10 UHS-I with microSD Adapter from Transcend features maximum read and write speeds of 45 MB/s and 25 MB/s, respectively. Its Ultra High Speed Class 1 (UHS-I) bus interface enables it to achieve these speeds, which are far greater than the 10MB/s minimum speeds guaranteed by the Class 10 rating. A microSD adapter is supplied, allowing you to use the card in a full-size SDHC/SDXC slot. The card features built-in Error Correction Code (ECC) to automatically detect and fix transfer errors. It is backed by a limited lifetime warranty.