ICY DOCK TurboSwap MB171SP-B Tray-Less 3.5" SATA Hard Drive Mobile Rack with 80mm Cooling Fan. Tray-less designs have always been a trade-off between convenience and security, but that's not the case for TurboSwap MB171SP-B. The ICYDOCK TurboSwap MB171SP-B keeps all the benefits of the tray-less design with superior build quality, improved cooling efficiency and its unique shock absorbing design for maximum stability. It fits any standard 5.25" bay and is built rugged with all metal design to take a beating. This lockable mobile rack is designed for rugged applications such as medical & military systems, industrial PCs and servers. It includes features such as drive power button, ultra-slim 80mm cooling fan, fan speed control and optional screw holes for an add-on 120mm cooling fan which can be great for gamers and power users seeking a hot-swap bay built in to their system with SATA III support.