ICY BOX SINGLE enclosure for 4x HDD/SSD with USB 3.1 (Gen 2) Type-C interface and fanFeatures: It's the mix Apart from the improved design, the advantage of the IB 3740 C31 is that it can support 2. 5" and 3. 5" drives. This makes the device an ideal candidate for users looking for the maximum amount of direct attached storage space since traditional spinning disks can accommodate a significantly larger amount of data than the largest solid state drives. If you're looking to eke out maximum performance, however, you'll want to use 2.