The ICY DOCK DuoSwap MB971SPO-B combines a 3.5" hot-swap drive bay with a 9.5mm ultra-slim ODD bay all in a single external 5.25" bay. The tray-less design makes it hassle-free to install or remove 3.5" hard drives simply slide in the bare 3.5" HDD and it's connected. There's no need to deal with screws trays or tools. Its quick-release drive ejection button makes swapping drives easier than ever with a spring-loaded arm that pops the drive out. The power switch and LED status light give you full control over connecting your drive. The bottom bay lets you install any 9.5 height ultra-slim optical drive making it easier to view and transfer your optical media storage such as CD DVD and Blu-ray medias. Both the 3.5" drive and ultra-slim ODD device are powered by a single 15-pin SATA power connector reducing cable clutter and adding space efficiency to the system. Optionally an additional ICY DOCK 2.5" HDD / SSD hot-swap kit can be added to the 3.5" drive bay or optical bay of the MB971SPO-B if access 2.5" (laptop) drives is required.