Was looking for a simple way to store the small, round digital hygrometers in the center of a spool when in a vacuum bag.  Most all the models come with a desiccant holder included.   Figured I would just design my own.

This holder fits spools with a center hole diameter between 49mm and 56mm and works with the brand of hygrometer I bought below.   But should work with any round hygrometer with a diameter of 40mm - 45mm (bottom diameter to overhang diameter of hygrometers below).

https://www.amazon.com/dp/B098JFRNKM?ref=ppx_yo2ov_dt_b_fed_asin_title

Print Settings
Layer Height: 0.15mm
Infill : 15%
Supports:  None
Materials Tried:  PLA