Computer has a tray that you put a 3.5 hard disk in and then insert the tray into computer

Adaptor for 2.5 inch hard disk to fit into a 3.5 inch hard disk location.

Tray is also much shorter that the standard screw location for a 3.5 hard disk.

Great for installing small drives in standard hard disk bays

It is just perfect, perfect for for mount a laptop hard disk in my desktop pc.

Internal Hard Disk Drive Mounting Kit / Bracket for fifty cents more and had absolutely no problems with that unit.