ALWAYS HAVE A CLEAN BOTTLE READY: 4-pack of replacement plastic breastmilk storage bottles for Baby Brezza 20 oz All-day Breastmilk Portable Coolers; Bottles nest easily inside cooler's ice packs, securely storing breastmilk; Each bottle holds 10 oz BABY-SAFE, NON-TOXIC MATERIALS: Milk bottles are made from high-quality, food-grade, lead- and phthalate-free plastic; Can be directly used in baby Brezza bottle warmers to safely warm cold breastmilk MESS-FREE AND EASY TO USE: 100% leak-proof lids; Cap easily twists off; Easy to read markings EASY TO CLEAN AND STERILIZE: Dishwasher-safe, freezer-safe, and microwave-safe; Also safe for use in the Bottle Washer Pro or any Baby Brezza Sterilizer Dryer CONVENIENT CAPACITY: Each bottle holds 10 oz of milk, up to 2-3 pumping sessions each; Complete 4-pack can store breastmilk from up to 20 pumping sessions