Calypso Breast Pump Upgrade Set is an add-on to convert the Calypso Single Electric Pump into a Calypso Double Electric Pump. The pumping time is reduced by up to 50%, the milk production is increased and the milk ejection reflex accelerated. A excellent choice for the busy working mother. Each Calypso Upgrade Set comes complete with 3 different breast shell sizes to cater to different women's needs & nipple size/shape changes during the lacation period. Additionally, the Optiflow Massage Insert is also included. Thanks to its air-chamber system and thin membrane, OptiFlow actively massages the breast and ensures efficient and comfortable pumping.