SATA to USB adapter with a 12V power adapter. I bought this to read data from a 3.5-inch hard drive, but I no longer need it, so I'm selling it. I've only used it twice, so it's practically new. For 3.5-inch hard drives, a 12V power adapter is required for SATA. For 2.5-inch hard drives, a power adapter is not needed; you can use the SATA to USB adapter alone.