Two Built-in USB ports can be used as USB hub to connect various peripheral devices. Supports ‘Port Multiplier’ function enabling two SATA HDDs to exchange data through a single USB connection and supports 2.5” and 3.5” SATA I/II HDDs up to 6TB(3TB for each slot). Two slots for multi card readers support SD, SDHC and micro SD cards. Supports data transfer rates up to 3Gbps through eSATA or up to 480Mbps through USB 2.0 interface. The Port Multiplier enables two 2.5” & 3.5” SATA Ⅰ/Ⅱ HDDs to read and write simultaneously and exchange data through a single eSATA or USB2.0 cable.