Giá đỡ spool cho hộp cereal 4L

I tried several other similar designs and found that they did not fit correctly for the cereal boxes I purchased, so I make a new one that fit my boxes correctly. These hold rectangular hygrometers as you can find here https://amzn.to/4qTkCcG

The style of cereal box is like this https://amzn.to/4qP8Hwo

There is a bridge section to be aware of. You shouldn't need supports, but ymmv