Pump In Style Advanced is a daily use double electric breastpump designed for moms who pump several times a day. All Pump In Style Advanced breastpumps offer portability for discreet pumping anywhere. The Backpack features a convenient built-in pump. Why 2-Phase Expression® technology? 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. Features Benefits Double electric daily use breastpump Designed for moms who pump several times a day. Built-in pump Portable and discreet. Stylish microfiber backpack Holds everything you need to pump. Battery pack Lets you pump anywhere, anytime. Single knob speed/vacuum adjustments For comfortable pump settings. One touch let-down button Produces more milk in less time when pumping at Maximum Comfort Vacuum™ in the expression phase. Removeable cooler bag with contoured ice pack Holds 4 bottles to keep breastmilk cool. All parts that touch breastmilk made without BPA IMPORTANT: This product is a single user product. Use by more than one person may present a health risk, performance questions, and voids the warranty. 1 - Black microfiber backpack with integrated motor unit 1 - Double pumping kit with 24 mm PersonalFit™ breastshields, includes connectors, valves, membranes and tubing 4 - 5 oz/150 mL breastmilk bottles with lids 1 - 9 volt AC adaptor 1 - Battery pack (8 AA batteries not included) 1 - Removeable cooler bag and ice pack Instructions for use in English/Spanish/French Breastfeeding Information Guide