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