I was looking for a Gridfinity box for my hygrometers. I couldn't find one, so I decided to create a simple version on my own.

The model is based on a 2x3 baseplate without holes for screws or magnets, the height is 8 (based on Zack's original calculation method). It can fit up to 7 hygrometers. The compartments for the hygrometers are 46mm x 16mm and scooped, so all hygrometers up to this size should fit as long as they're round.

The box also has a lid so it's stackable.