USB Card Reader, UtechSmart USB 3.0 Multi-in-1 4-Slots Card Reader Easy to take, use and install, no additional software installation required. Super-Speed USB 3.0 interface, backward compatible with USB 2.0/1.1. Drastically improved connection speeds compared to older USB 2.0 card readers. Subject to the speed of memory card itself, only the SDXC card can reach the speed of USB3.0 now USB Bus Powered: no external AC power supply required.