You may access the interior by removing four small screws holding the top panel in place. Once opened, the interior shines in the same cold, unpainted steel as the rear of the chassis, which aids in passing EMI testing. The most noticeable element is the support bar including four expansion slot anti-sag brackets. It should also be mentioned that there are a lot of sharp edges inside the chassis, which is not unusual for server enclosures, unlike consumer products.
In the front of the SilverStone RM42-502, you will find a cage for the two 5.25" drives, but it has been engineered to allow for either a total of up to four 2.5" or two 3.5" drives. Naturally, you may go with a mix—say, two SSDs and a spinning drive, for example. In addition, there is a separate bracket for a single 2.5" drive on top of it all. This setup may not seem like a lot for a server chassis as storage is the most prominent use case; however, the RM42-502 is meant to be used for computing purposes, not data storage. In the other corner, you will find a support bracket for extra-long specialty expansion cards right in front of that single 120 mm intake fan.. Interestingly enough, all cooling units within the case are from BeCool.
In the rear, you can clearly see the seven expansion slots, each protected with a reusable cover and held in place by a classic screw. The 80 mm fan inside the RM42-502 comes with a short cable to attach to the PWM header in the top-left corner of your motherboard.
As this is a server chassis, SilverStone includes an open chassis sensor with a 2-pin header, something server boards tend to offer, but some consumer variants do as well. You may remove all major components from the case, including the motherboard tray, drive cage, and expansion slot support frame, to make your assembly process as easy as possible. This is really where you notice the sharp edges on some of the parts, where other cases have folds to eliminate chances of getting a cut.
All the cables within the RM42-502 are sleeved black, and SilverStone actually employs flat cables for both the USB 3.2 and USB Type-C cables, which is nice to see. That said, all connectors are of the default variety, so they will work with retail motherboards just as well.