I wanted to know the moisture level of my dry boxes without having to cut holes and sealing the holes up. Though I keep my spools vac sealed with desiccant bags, I wanted to know the effectiveness of the dry boxes themselves. This holder was designed for this hygrometer I purchased from Amazon. Though slow to adjust, it does eventually match my Thermoworks hygrometer within +/-3% for humidity levels and +/-1 degrees F.

To install, I just scuffed up with sandpaper the location in the box I wanted it. Then just applied a tiny amount of super glue to the flanges of the holder.