These containers are made of thick plastic and the great thing is that the lids are interchangeable on all of the containers.
My only problem was getting the lids on at first - there is a technique I think in getting them aligned on one side and then clicking into place on all other sides. I can see many uses for these - of course for dry goods in the kitchen - but I think I will find uses all over the house - we camp a lot and I already know I will be using these for food and supplies since they are extremely sturdy and look to be air tight. They also come with cute little black stickers and a pen to write contents on-
This was a really great purchase for the price and I would buy again.