This 6" cable is used for powering SATA drives. Serial ATA drives have a special 15 Pin Power connector this converts it to the standard 4 Pin Used on most power supplys. This cables is required for all Serial ATA Devices. Standard 4-pin Molex Drive Power Female adapter to 15-pin SATA Power Plug Used to convert Standard Molex Power 4-pin (IDE drive Power Plug) to New SATA and SATA II Hard Drive Connector