Here is how the enclosure does look with a 9.3mm OCZ Vertex 4 drive installed; as soon as we do have the drive secured, the Eject button becomes accessible:

Thanks to the included Safety Enhanced Drive Guiding Mechanism, ICY DOCK does prevent accidental drive ejection; two guiding pecks on either side of the drive and a metal flap in the rear does adjust automatically based on the height of the drive. Each guiding pecks clamp the drive tightly while adjustable metal flap pushes the drive down, making a stable SATA connection:

Let’s say that you are in the situation when no available 3.5’’ bays are available on your case; ICY DOCK has also thought of a solution so they are proposing the FLEX-FIT Trio solution, which does basically convert 3.5’’ to 5.25’’, but also provides two additional 2x2.5’’ SSD/HDD drive bays on top:

On the lateral sides of the FLEX-FIT MB343SP, ICY DOCK does describe the HDD/SSD tool-less installation procedure; if we do not choose to install the FlexiDOCK MB522SP-B inside the provided 3.5’’ slot, we can always go with a 3.5’’ HDD:

Additional technical specifications are available on the back side of the box:

The FLEX-FIT Trio MB343SP along with its bundle is further wrapped inside a transparent plastic bag:

In order to secure the drives even better, the necessary screws are also provided (for installing a 3.5’’ HDD, a 3.5’’ device/FDD but also for the FLEX-FIT Trio itself:

The installation procedure is described with details inside the provided manual: