The renkforce sata duplicator and eraser dock allows connecting two 25 64 cm or 35 89 cm sata hdds to your pc without the need to install the hardware in your pc or to use an external hdd enclosure connecting the dock to a pc via usb 30 cable included the led lights indicate power supply and data transfer rate press eject to disconnect and remove the hard disk drive if you connect two hard disk drives the duplication process doesnt require a pcduplicating beats re installing