External SATA (eSATA) cables are designed to connect external SATA devices to either external SATA ports or internal SATA connectors. Unlike cables for internal applications, eSATA cabling must be shielded. The eSATA connectors are keyed differently, to prevent the use of internal SATA cables in external applications. While internal SATA connectors have an "L" shaped key, eSATA connectors use smaller, vertically offset keys.

This shielded eSATA cable is certified to perform to SATA 6 Gbps performance standards. One end is terminated in an eSATA connector, while the other end is terminated with an internal SATA connector. By routing the cable through an opening in the system case, you can use eSATA devices with a system that is only equipped with internal SATA ports.

Note that SATA 6 Gbps cables are backwards compatible and can be used with SATA 3 Gbps and SATA 1.5 Gbps devices. However, the data transfer of the SATA subsystem will be limited to that of the slowest device. So, for example, if a SATA 6 Gbps cable is connected to a SATA 3 Gbps drive and a SATA 1.5 Gbps controller, the drive will be limited to a transfer rate of 1.5 Gbps.