Medela bottles can be used to collect breast milk with any Medela pump set, to store expressed breast milk in the refrigerator or freezer, and to attach the Calmita feeding solution. All disposable bottles feature laser-print graduation for accurately measuring the milk volume pumped or fed. The disposable Colostrum Container has a curved bottom to minimize loss of colostrum. The bottles and Colostrum Container can be used straight out of the packaging. There is no need for cleaning prior to first use. Come handy especially when travelling!