Yeah, OK, Thread ID tools are pretty easy to find, but that didn't stop JON-A-TRON from wanting to design his own. The great thing about being able to design and fabricate your own tools is that you're able to customise them to suit your needs; In this case, JON-A-TRON wanted a tool to identify only his most commonly used nuts and bolts for projects. He was also able to space everything further apart than on similar tools, giving better ease of access.
The majority of the case was 3d printed, with the top being laser engraved. This can be easily customised for your needs by adding whichever size nuts and bolts you most commonly use. If you don't have access to a 3D printer, you could also laser cut the entire case. The files for the exact tool pictured are available on the Instructable, and he also shows you the design process so that you can add and remove sizes as needed.