It OPENS! What shall I store in here? Hmmmmmmmm! 

What's this!? A box!? 

HDD cage by itself 

Without the box. Supposedly it's possible to stick another fan here. Also, that little space right below the black plate at the bottom of the pic is where my 3.5" drive or whatever will go here.

This one slides out too! Really CRAZY!!!!! 

Without the box inside 

Without the white box inside 

It slides out! That's CRAZY!!!!! 

Can place more HDDs here if I what too. :D 

HDDs, DVD drives, and what not goes here