The Rugged Case is a hard-sided storage box, and Roam makes it in more sizes than almost anyone: 55, 66, 76, 83, 86, 95, 105 and 160 litres, plus 128 and 150 litre rolling versions with wheels for the sizes that get too heavy to carry loaded. That range is the point. You pick the case that fits the space you actually have, whether that is a bed rack, a cargo area behind the second row, or the floor of a drawer-free 4Runner.
The accessories turn a box into a system. A lid organizer uses the flat space inside the lid for the things that get lost at the bottom of a case: straps, gloves, tools, a headlamp. A MOLLE panel gives you a webbing grid to hang pouches from. Rigid mounts bolt the case to a rack, a bed or a platform so it does not slide around or need ratchet straps every time you load up.
Not every accessory exists for every case. Lid organizers are listed for the 55, 86, 105, 150 and 160 litre cases, MOLLE panels for the 105 and 160, and rigid mounts for the 76, 86 and 105. Check that the accessory you want is made for the case size before you commit to a size. Roam does not publish material or ingress-protection ratings on our end, so if you need a specific waterproof or dust rating in writing, ask before ordering.