Weighing less than a pound, the Duo is designed for travel and work and stays charged for over 2.5 hours. It can operate on Massage, Expression or Memory Mode and mom can adjust between 10 suction levels. Includes 21, 24, and 27mm breast shield sizes. The Duo pump comes with a Hands Free Pumping Bra included so you can truly get the on-the-go pumping experience!