Product came with mismatched backflow preventers- one that fits the Maymom tubing and one that fits the original Spectra flange. For Spectra S1: When used with original tubing plus the long Maymom tubing, there is no suction (pump loses more power the longer the tubing is). You need to use the short tubing between the Freemie cup and the backflow preventer, the Spectra tubing between the backflow preventer and the pump. I did this, turned the pump on, and (ouch, unpleasant surprise) suction was See full review