I use these inserts so that my filament rolls do not lie in the silica balls. I used to use small containers for the silica balls. But I had to change them every 2 weeks. Since I have the inserts and the whole bottom is covered with silica, I rarely have to change the granules.

The diameter of the insert is 180mm(7.08in). There are two versions, one 12mm (0.47in) high and one 8mm (0.31in) high. The dry box can be ordered from Amazon.

I have also included an adapter to accommodate a hydrometer. The hydrometer can also be ordered from Amazon (Thlevel Mini LCD Digital or search for Mini Hygrometer Thermometer Electronic Digital Humidity Meter Gauge Monitor LCD Display) .