Sturdy Borosilicate Glass: These containers are made from high-quality borosilicate glass with sealed polypropylene (PP) lids to prevent oil absorption and chemical leaching. You can easily see the contents inside without breaking them when safely transferring from the refrigerator to the oven or microwave (lid not included). Sealed glass storage jars keep food fresher for longer: Silicone seals and secure lids allow you to store snacks or sauces without bringing in odors or air, ensuring freshness. Their stackable design makes organizing these containers easy. Our prep jars take up very little space in the kitchen Very easy to maintain: It can be safely placed in the dishwasher, but ensure it is on the top rack. Glassware is very easy to clean and leaves no odors or stains. The rubber seal can be removed and easily repositioned after cleaning