The Western Digital HDD SATA to USB Control Board 4061-705210-C00 AC Adapter is a portable external HDD that connects to computers via a USB interface. Designed specifically for HDD drives, this adapter allows users to easily connect their external HDD to their computer for data storage and access. With the trusted brand of Western Digital, users can expect reliable performance and compatibility with their HDD drives. Ideal for those looking for a convenient and efficient solution for accessing their external HDD on their computer.