Premium Glass Construction: These containers are made from borosilicate transparent glass, known for its ability to tolerate rapid temperature changes without warping or cracking. Safely transfer these containers from the freezer to the oven, without a worry. Environmental and Health Safety: Unlike plastic containers, these glass versions are eco-friendly and free from harmful chemicals. Hot foods can be directly transferred to the containers without the risk of chemicals leeching into the food. Additionally, the lids are crafted from BPA-free plastic, ensuring your safety. Versatile Usage: Perfect for microwaving with the lid vent open, as well as safe for the freezer, dishwasher, and oven (without the lid). These containers won't absorb stains or smells, keeping your food tasting fresh for longer. Easy Cleaning and Storage: Designed for a hassle-free experience, these containers are dishwasher safe and easy to store.