HIGH QUALITY GLASS: Made from premium quality borosilicate glass, these glass meal prep containers are microwave, freezer, and oven safe, allowing you to conveniently heat up your meals, freeze leftovers, or even bake and reheat dishes, ideal for daily use. Please take off the lids when heating your meals. AIRTIGHT SEAL: KOMUEE glass storage container comes with a plastic lid with silicone ring that creates an airtight and leak-proof seal, keeping your food fresh for longer and preventing spills or leaks. These BPA-free lids are easy to use and will not break off easily. VERSATILE USAGE: Each meal prep container has a capacity of 22oz, making it suitable for portion control, meal prepping, and packing lunches for work. Ideal for storing a variety of food items such as salads, snacks, leftovers, and more.