Pump In Style Advanced is a daily use breastpump designed for moms who pump several times a day. All Pump In Style Advanced breastpumps offer portable convenience for quiet, discreet pumping anywhere.The Metro Bag features a removable pump in a separate bag for pumping and trasnsport flexibility.Featuring the original 2-Phase Expression?technology - only found in Medela breastpumps. Through research, Medela learned that there are two distinct phases of how babies breastfeed. Stimulation Phase - when babies first go to breast, they suck fast and light to stimulate milk flow. Expression Phase - after milk flow or "let-down" starts, babies breastfeed with a slower, deeper suck, bringing out more milk faster. This is definitely a wonderful breast pump that new mothers will definitely enjoy.