Perks \tThis pump utilizes a closed system which prevents milk from entering the tubing \tTwo phase pumping kit: Expression and Stimulation phases mimic your baby\u2019s natural feeding patterns. This feature helps moms pump more comfortably \tMaximum Comfort Vacuum setting in the Expression phase helps produce more milk quickly \tThe backpack has a built-in pump for easy storage and travel \tThe cooler bag can hold up to four bottles and allows you to bring milk with you or store your milk supply after pumping. The contoured ice pack is included with the cooler bag and is specially designed to hold Medela bottles, keeping them cooler for longer periods of time \tWith multiple power options, you can pump without an outlet \u2014 use the battery pack option or an AC adaptor \tEasily adjust speed\/vacuum pumping settings with a single knob \tSave your favorite speed and vacuum settings with the memory button \tThe double electric pumping option allows you to pump both breasts at once, expressing more milk in less time \tAll Medela parts that come in contact with breast milk are made BPA free for the health and safety of your baby This Pump is Perfect For\u2026 Moms on-the-go \u2014 This is a perfect option for moms who plan to be out and about and will need to pump. The breast pump is lightweight and is easily stored in a briefcase or carrying bag. What\u2019s Included \t(2) Connectors \t(2) Valves \t(2) Membranes \tTubing \t(2) 24mm PersonalFit breast shields \t(4) 5 oz. Breast milk storage\u00a0containers \t9v AC adaptor \tBattery pack \tBlack microfiber backpack with built-in pump motor \tCooler bag with ice pack fits inside the tote \tUser instructions \tBreastfeeding informational guide What to Look Out For When pumping on-the-go, you need to make sure you have a suitable power option with you at all times. The battery pack allows you to pump without a power source, whereas the AC adaptor requires an outlet.