FOOD-SAFE MATERIAL FOR BABY: To ensure babies’ safety and health, we are surely serious about the choice of materials. The glass of the container body is high-quality food-grade glass that is impeccable over plastic and normal glass, and it is more durable and sturdier that is thicker than others to keep that they would be used for a longer time. Besides, they are totally BPA Free, phthalate free and lead free even with premium plastic lids on. Mommies can use them with ease and confidence. | EXCELLENT AIRTIGHT SEALING & STACKABLE: There’s a food-grade silicone ring in the lid to provide super airtight sealing, so that the food inside can keep really fresh and clean, and avoids to be polluted or spoiled. And airtight also means leak-proof that if carried outside, you do not need to always pay attention to whether food is spilled or leaked. And the design of the lid makes them stackable to get easily distinguish and space-saving storage. | SAFE FOR FRIDGE & MICROWAVE OVEN & DISHWASHER: To store, the containers can be put in the refrigerator, and freezer for longer storage. To heat, the containers can be put in the microwave oven or oven, but please note that the lid needs to be removed or the lid cannot be put into the them. To clean, the jars can be washed in the dishwasher. | 4OZ REGULAR CAPACITY WITH SCALE MARKS: 6 packs of the set, each of 4oz. Great and enough for daily baby food preps. And with the engraved measurements, It can be quickly and accurately filled to the desired capacity. The whole capacity up to 4oz if you fill it to the very edge of the jar, but the scale marks on the body show up to 2oz to make sure you can clearly see the capacity from the outside without opening the lid. | MARKABLE FOR VERSATILE USES: The marker included in the package is for writing names, dates or other information on lids to remind you what’s inside or when made it. The dry erase marker makes it rewritable and reusable. Very nice to store homemade baby food, solid baby food, fruit & veg puree, mashed avocado, jams, sauce, pesto, etc. Also a wonderful gift choice especially for a baby shower.