Size of them is versatile, from tall to a smaller size, they are easy to layer up to be very room friendly. The materials are solid PVC plastic, both tenacity and impact are meet with home appliance standard. It still need to used for months to see if there is any shrinkage. Seal fastness, I find the rubber around the lid seal up to the container snuggly. There is no concern about moisture, cause it is sealed tight.
