This enclosure is specifically built for RAK7243 Pilot Gateway, a RAK product that is composed of a Raspberry Pi 3B+, RAK2245 Pi HAT, and an optionalRAK2013 Cellular Pi HAT. This enclosure is made entirely from aluminum material with outer dimensions of 92mm x 68.3mm x 53.5mm. It is durable and designed for indoor setup (rated IP30). Please see this guide on how to assemble the boards inside this enclosure.
Which components are this Aluminum Casing designed to accommodate besides a Raspberry PI3+?
This can also fit our Commercial Gateway Boards, we do have the RAK7249 which is a preassembled Gateway with the board included. You can also take apart a RAK7258 and put the board in the casing to make a low-cost weatherproof Gateway.
As for other components, you can do DIY builds with the RAK2245.
Naturally, you can install your own components, however, you do need to take into accounts how you are gong to mount the provisioned power, etc. The case comes with a Gland and an auxiliary port so this should not be a problem.