Hands-free, cord-free in-bra wearable pump with 21mm and 24mm flangesCompatibility with Willow Go app for both iOS and Android, lets you keep track of your pumping sessions from your smartphoneMobile and compact design ensures ultra-quiet and discreet operation with its all-day battery life that can last up to five sessionsFlexible capacity allows usage of either 5oz. or 7oz. containers (sold separately)Easy setup and clean-up design with just five dishwasher-safe parts to cleanComes with two pumps, two 21mm flanges, two 24mm flanges, two container backs, two 5oz. container bowls, two pump diaphragms, two duckbill valves duckbill valves, and two USB charging cables