This is a case for an Xbox 360 Slim Hard Disk Drive. I got a new Xbox 360 E 4GB Version and somewhere on the internet read about using my old xbox HDD, so I tried it and it worked fine, the only problem I found was it is loose on the tray. This thing was inspired on http://www.thingiverse.com/thing:122167 It has a space for a small tape to help get the disk out the tray. I hope you find it useful, if you want to modify my design you can download the Solidworks (v2014) part file. Regards!