Made of safe POLYPROPYLENE these containers and lids are engineered for heat and cold resistance. It’s thick walls keep cold items cold and hot items hot. The containers are microwavable making these the ideal take out container. These come highly recommended as food savers for people who like to cook in batches as a perfect meal prep container. They are easy to stack in coolers and picnic baskets. Great to use for assorted chips or fruits. Think outside the box! Also the perfect container for arts & crafts. Use to store crafts and paraphernalia by color or size. Save paintbrushes and crayons. Hassle free woodworking & home repair - organize little wire nails or screws. CLEAR LID for easy viewing of contents.