The breast pump is a mechanical way of collecting milk and is used either when the mother is unable to breastfeed on her own or when she needs, for whatever reason, the newborn to leave, more often in case the mother wants to return to work. This particular "Made for Me", by Tommee Tippee, is manual, fits securely on the chest creating a natural suction. It also has a built-in bottle for collecting milk while it is easy to clean and sterilize. How is milk stored: It is best for the milk, after being pumped, to be offered directly to the baby. If the mother wants to store the milk, she can keep it in the refrigerator, in a bottle, for up to 5 days or freeze it for up to 6 months in a sterile glass bottle. The milk can be left at room temperature for up to 6 hours.