The Medela Swing Flex breast pump has evolved to become the Solo pump. The Solo is a simple, effective, and compact electric breast pump with a built-in rechargeable battery, 2-Phase Expression® technology, and a PersonalFit Flex breast shield. • Easy to use: Intuitive 4-button interface and 9 pre-programmed settings. Easy to assemble and clean with few parts. Lightweight and compact design. Improved mobility: Built-in rechargeable battery for up to 6 pumping sessions on a single full charge. Faster charging with the USB Type-C port compared to the microUSB port. 2-Phase Expression® technology simulates a baby's natural sucking rhythm.1, 2. PersonalFit Flex breast shield for greater comfort and 11.8% more milk. Much quieter than the previous generation at less than 45 dB at maximum pumping level. The closed system prevents breast milk from entering the tubing.