This drive bay transfer bracket allow 3.5 inches drive size devices to be mounted in standard 5.25 inches drive bays. It works with 3.5" & 2.5" HDD and slim DVD drives. Features: this drive bay mounting bracket has 3 combinations to fit HDD/slim DVD into a 5.25" drive bay, maximize the internal space of your computer case for efficient usage, work with 3.5" & 2.5" hard drive and slim drives, different size screws included for mounting the bracket into the PC case.