This project would be a lot more difficult for others to replicate if they have to fabricate their own enclosure. Sure, making a wooden box for the base station wouldn't be too difficult. But the transmitter needs a sealed - preferably IP67 or better - case. And lugging around some big NEMA box won't fit the bill, either. So I needed to track down a suitable off the shelf case, small enough to easily tote about, and preferably with a form factor that made it easy to wear. And it would be best if they were something the average hacker can order just one of, instead of something with a MOQ of a couple hundred.

Hammond is a pretty common go-to company for project boxes, but their smallest sealed plastic box was about 4" x 3". Workable, but not ideal, and putting it on a lanyard would require drilling a hole for mounting hardware. I'll keep them in mind in case the final circuit board turns out to be too large. And their plastic cases have some good candidates for the base station.

After searching several other suppliers, it turns out OKW already offers a lot of cases intended for medical equipment, and they happen to have a case designed especially for tiny wearable devices: the Body Case. They even offer lanyards and wrist bands. At $14 each, the case is a bit more expensive than an Altoids tin, but is perfect for this application.