The MB671SK series is the first and many of our internal screw-less enclosure. It provides the user with tray-less easy hard drive access and hot-swap capabilities without having to screw in a tray. The enclosure is built to fit most 3.5" SATA brand hard drives and uses a steel metal body to create a perfect cooling environment for the hard drive. The built-in fan and front ventilation system further prevents the hard drive from overheating. But we have not disregarded issues of security as we installed an access key lock to prevent any hard drive thefts. Exchanging hard drives is quick while provides flexibility in reducing overall costs for your system.