The Drobo Mini is one of the most innovative and useful devices we've seen in a while. Like a miniature version of its eight-bay B800i array, the Drobo Mini provides space for four 2.5-inch SATA hard drives or SSDs of 7mm or 9.5mm height with no carriers, trays or tools required. There's no maximum drive capacity. With all four bays populated with 1-TB drives, the Mini would provide 2.72 TB of available storage and use the remainder for data protection. A safer, dual-disk redundancy option divides total available capacity approximately in half.