The RhinoJR RJR400 allows up to four low-profile Serial ATA (SATA) drives to be installed into any three 5.25 inch, half-height, system-internal device bays for convenient removal or exchange. The cost-effective RJR400 design is ideal for internal server RAID and JBOD applications. - Supports any Four SATA Drives. - Downward Compatible. - Mounts into Three 5.25" Half-Height Bays.