The S2 boasts so many great features and is designed to truly meet the needs of moms wanting to feel confident that they have an effective, powerful breast pump to support supply while also incorporating features to make life a little easier. Like all Spectra pumps, the S2 is a closed system - a physical barrier between the milk and the pump ensures hygiene and motor performance. With a maximum suction strength of 250mmHg and the ability to be used as a single or double pump, plus a host of additional features, the S2 is set to become the ultimate breast pump to support U.S. moms. The S2's completely flexible, touch button, with the S2 pump's digital controls allow you to set the pumping program to the speed and rhythm most effective for your body. The suction is adjustable in both let-down and expression mode. This quiet pump also includes a timer and night light