This external eSATAp cable integrates both data and power signals into a single lead. It connects an external SATA hard disk or similar device to an eSATAp port. It can connect both 2.5\" and 3.5\" hard disks as it provides both +5VDC and +12V DC so can be used with both desktop and laptop computers (see note below). This cable is compatible with the latest generation of computers and interface cards that support power over eSATA. The cable may be used in conjunction with our 2 Port Power over eSATAp +USB PCI Express card and Power eSATA & USB 2.0 Adapter Card. Note: Laptops typically supply up to 5V from the eSATA port, which is suitable for use with most 2.5\" HDDs and SSDs; desktop computers typically supply up to 12V, which is suitable for both 2.5\" and 3.5\" drives. Please check that your computer\'s eSATA interface port supports power before using this cable.