This log answers the Production requirement for the Hackaday 2020 prize entry rules:
Production-Is the project realistically reproducible (taking into consideration necessarymaterials, skills, and production processes)? Are the manufacturing processes detailed? Are those processes realistic for scalability?
The design comprises of two microbits and one wrist holder plus associated code. There are over 1.5 million microbits already produced. Microbits cost around $15 each. So obtaining these does not require any production.
There are wrist holders commercially available, though I prefer my home made one. It would be straight forwards to ask a fabric shop to do a production run of wrist holders based on my home made one. Otherwise commercially available wrist holders can be used.
The code is on my GitHub site, so can easily be replicated.