Superior Quality 9.5 mm caddy for hard drives Encouragement 2.5" SSD or SATA HDD disk, 7mm or 9.5mm Encouragement Maximum Speed Up to 6 Gbps for SATA III, SATA II, and SATA I Encouragement Hot Swapping Idea: Add a second SATA HDD or SSD in place of your optical drive SuperDrive (DVD/CD-ROM).