Round glass dish: healthy and hygienic material, does not retain stains or odors - Borosilicate glass base: resistant to extreme temperatures, from -40°C to +300°C, and to thermal shock - Base with handles for easy grip and to prevent burns. - Lid with 2 steam vents, for reheating your dishes in the microwave with their lids on. - Patented secure lid with easy-to-use sliding clips to keep food fresh