This product is designed to work with Medela Breastpumps such as Pump in Style Advanced, Lactina, Swing, and Symphony. It is interchangeable with Medela Valves and Medela Membranes. It can attach to Medela PersonalFit connector and one-piece breastshield. On the other hand, it is not designed for Medela Freestyle pump nor Medela Swing-Maxi pump (a double pump). It can also replace duckbills in Spectra S1, S2 and 9 Plus pumps that use NARROW Mouth flanges and the valve/membranes used in Spectra Dew 350 pump. For S1/S2 that have the wide-mouth flanges, don't buy from this listing. These valves are a little bigger than needed.
- It is interchangeable with Medela Valves and Medela Membranes
- It can also replace duckbills in Spectra S1, S2 and 9 Plus pumps that use NARROW Mouth flanges and the valve/membranes used in Spectra Dew 350 pump