The supported hardware are exposed boards. Keeping your new hardware away from water and dirt is always going to be important to ensure it lasts. Many manufactures produce cases for their hardware and there are also a range of options available online start from as little as 3-4USD.
Alternatively, you can 3D print your own case. We provide the design files you can send to have printed. Generally, this option works best using local providers. Schools and community centres increasingly have 3D printers that you can use too. Alternatively, CraftCloud3d provides a search engine to compare prices in your area.
Generally, 3D printing is cheaper if you have access to a printer or if you require multiple cases. If you only need 1 or 2, then costs of printing and postage can begin to add up.