The Medela pump in style advanced power adaptor is compatible with all Medela 9-Volt pump in style advanced breast pumps and is conveniently dual-voltage for 110 - 240V, allowing moms to easily use their pump in style advanced breast pump while traveling outside the U.S. The Medela pump in style advanced power adaptor is an easy and convenient replacement option for moms to have an Extra power supply on hand whenever needed, replace a damaged power supply, or keep a dual-voltage power option when traveling outside the U.S. Please Note that using the pump in style advanced power adaptor outside of the U.S. Requires a universal prong Connector, which is sold separately and is not a Medela Item. Medela 2018 U.S. Breast milk feeding Report. Medela global brand assessment study 2017.