This is an adapter is for connecting internal storage devices that require 15 pin SATA power connectors to Power supplies that only have 4 pin molex power connectors.
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. This shielded eSATA cable is certified to perform to SATA 6 Gbps performance standards. Each end is terminated in an eSATA connector for use with external SATA devices and controller ports only.