External USB docking station is forward and backward compatible with all RDX cartridges. Using a removable disk cartridge (sold separately), the docking station backs up just like a tape drive and is able to back up more than 125GB of data per hour and give you access files instantly. Transfer rate (average sustained) is up to 25MB per second USB and 35MB per second SATA. Cartridge capacities range from 160GB to 1TB for flexible storage. Docking station is reliable for a minimum of 10,000 load/unload cycles.