The Lexar multi-card two-in-one USB 3.1 card reader offers transfer speeds of up to 312MB/s (reads up to five times faster than USB 2.0) for SD and microSD. It's also backwards compatible with UHS-I (up to 170MB/s), significantly improving your workflow. Save time with concurrent file transfers with the ability to read from both card slots simultaneously, and enjoy easy file transfer from one card to another, further enhancing the reader's versatility. Designed with a USB 3.1 interface, the Lexar two-in-one card reader is also compatible with USB 2.0 ports. All Lexar product designs undergo extensive testing in the Lexar Quality Labs, facilities with more than 1100 digital devices, to ensure performance, quality, compatibility, and reliability.