I use a 40g desiccant dry pack with each Print Dry container. The filament stays dry much longer than it does with an "air-tight" food storage container. I also have a piece of dry-erase tape on each container to indicate when it was last dehydrated. The system works for me.
Nearly impossible to separate these containers out of the package and they lose the air seal after a few days. I plan to reach out to the company and then will update this review.
These are great for dry filament storage, that is until you are able to pry them loose from each other. I had to use a hairdryer to warm them up a bit to be able to separate the stacked bottom section of the container before I could use them.
The product works as intended. Just a warning though, the bowls can come stuck together. When I mean stuck ... I mean stuck. Like bruise you fingers to get them apart and can't. I phone the company for assistance. They said they were correcting this issue with their supplier/manufacturer, but in the meantime use a flat ended long tool to pry them apart at the hinges. Well with some effort and being careful not to damage the bowls, it eventually worked. So don't be surprised if this happens.