These stackable refrigerator storage containers are made of high quality food-grade PP material, BPA-free, safe and non-toxic. They are transparent, allowing you to easily see the contents inside, and have a strong structure that can hold a lot of weight. The containers are stackable, saving space in your refrigerator, and have a flat bottom that makes them easy to clean. The lids are secure and leak-proof, keeping your food fresh and organized. They are suitable for storing a variety of foods, such as fruits, vegetables, snacks, and more. These refrigerator storage containers are a great way to keep your food organized and fresh, and are a must-have for any kitchen.