Elite Bastards posted a review on the Eagletech ET-CS2XMESU2-BK 2.5" hard disk enclosure

To open up the enclosure, a small tool is provided which clips to the device's stand - This can be used to press the small button (although to be honest a paper clip will do the same job) which releases the enclosure's mechanism and allows a 2.5" hard disk to be either added or removed. This method to open the device aside, installation is completely tool-free, as a suitable Serial ATA drive can simply be slid into the enclosure until it clips into place, or equally pulled out with ease to remove the drive.

Eagletech ET-CS2XMESU2-BK 2.5" hard disk enclosure Review