This nano is your reward for doing the Adventure Lab Cache...
Okay it used to be a nano, but since people kept losing them, it's now a micro!
IT IS NOT AT THE POSTED COORDINATES!
The only way to know where it is is to get the instructions from the Adventure Lab Cache.
Click on this link to get to the Adventure Lab cache:
https://adventurelab.page.link/hN41
Happy Caching!
Congrats to CT_91 on first to find for both this Mystery Bonus cache as well as all 5 stages of the Adventure Lab Cache.