Quality Borosilicate Glass: Built to last, the containers are made from borosilicate glass, known for its durability and resistance to temperature changes. You can safely transfer them from the freezer to the microwave without fear of cracking or warping. Sliding Steam Vent Technology: A unique feature that allows you to open the vent for microwave reheating, preventing steam build-up and ensuring even heating. Eco-Friendly and Safe: A sustainable alternative to plastic, these glass containers are friendly to the environment and free of harmful chemicals. They don’t absorb stains or odors, preserving the pure taste of your food. Versatile and Convenient: With varying sizes and a universal dark grey color, these containers are perfect for storing different meal options, from main courses to side dishes, snacks, and more. Microwave, Freezer, and Dishwasher Safe: The ultimate in convenience, these containers are designed for easy reheating, storing, and cleaning.