This 2 Port eSATA ExpressCard adapter lets laptop users experience the high performance capability of eSATA storage for data transfer rates of up to 3Gbps, as well as port multiplier capability with command-based switching for connecting multiple external hard drives to a host PC or Mac notebook through one eSATA connection. Using a native PCI Express single chipset, the eSATA controller provides enhanced compatibility, reliability and performance for your external storage needs.