Baby Brezza's All-Day Breastmilk Cooler keeps your breastmilk cold for up to 24 hours so you no longer worry that your breastmilk won't stay cold between pumping and refrigerating or freezing! This revolutionary new cooling system holds up to 600ml of breastmilk - which is milk from 4-5 pumping sessions on average! The double-insulated stainless steel thermos holds two 360 degrees ice packs that fully surround two 300ml reusable milk storage bottles, ensuring breastmilk remains cold until you can refrigerate or freeze it. It's easy to use - first, freeze the ice packs, then slide the frozen ice packs inside the stainless steel thermos. Simply add the milk storage bottles to keep milk safely chilled for an entire day! (Based on lab testing measuring the time that the coolers maintain breastmilk temperature at refrigerated levels). The internal milk storage bottles are dishwasher-safe. Features a built-in carry handle and twist-on/off lid for convenience and portability on the go, while traveling, or just at home between pumping sessions and a trip to the kitchen! PVC/Lead/Phthalate/Cadmium-FREE. 1 year limited warranty