The next step is installing the hard drive and optical drive. Before putting those in, you have to provide each of them with a special retention screw that will serve as a stopper.
Plastic clips on the case front panel have little slits in them.
We push the drives in along the rail runners until we hear a clicking sound indicating that the stopper is in the slit and dead locked. If you need to replace a drive in the future, all you need to do to remove it is to slightly bend the clip and pull the drive out.
The light metal color of my optical drive stood out against the overall black color scheme of the system, so I moved it to the upper bay later on and used the lower bay for cable management needs. As for the hard drives, they will be covered with an additional 92mm fan included with the case. Its only drawback is that it is of non-standard shape, so if it fails it will be really hard to find an adequately looking replacement for it. However, the retention holes for this fan will easily accommodate a standard 80mm one.
There are two lugs on one side of the fan frame and two latches on the other. Set the lugs into the slits in front of the HDD bay and push the frame in until you hear a familiar click.
The fan rotates at 2100 RPM, and to me it seemed a little too much. It is hard to slow the fan down, however, in most cases you may not even need to connect it, unless you have two hard disk drives, each with 1TB capacity and made of 4-5 platters, which heat a lot. You can just keep the fan there for aesthetic purposes, as a single HDD installed into this chassis will get all the cooling it needs even without the fan.