This is a 2.5" SSD/laptop HDD adapter. Its purpose is to fit a 2.5" HDD/SSD into a 3.25" hot swap bay.
This adapter is providing the shape and connections of a 3.25" HDD to any 3.25" slot including screw holes (where possible).
Therefor you can use it in any 3.25" slot although its main purpose is to adapt a 2.5" device to a 3.25" hot swap bay.
Changes to the original: better ventilation of the HDD and less filament required.