Define R3 Black Pearl has seven expansion slots and four holes for water cooling. A look on the rear panel reveals an important thing – the Define R3 is wider than classic midi-tower cases. The right side panel isn’t very close to the I/O panel, which is good as it means extra room for cable management. The expansion slot covers are fixed with thumb screws, which are also used to lock expansion cards. You can reuse the covers and the company made sure to improve the Define R2’s covers by including air inlets.
You’ll find dust filters on the bottom panel below the PSU. 
The bottom filter can be taken out for cleaning with a tug from the back of the case. It would perhaps be better if the filter had a small handle to make the task easier.
The feet are made with anti-vibration rubber coating underneath, and are stable and tall enough to allow the air to be drawn in from the bottom of the case. Although the plastic feet seem fine, they’re a bit funny as the rear ones are much smaller than the front ones.
