17mm Silicone Flange Insert | Reduce 24mm Elastic Tunnel Down to 17mm | for Spectra, Momcozy S9 S10 S12, Willow go Flange Inserts, Medela, Freemie Breast Pump Inserts Shields, 2PC

I bought these on a whim, hoping they would fit my Bellababy wearable pump. To my surprise, they do well. They aren't the snuggest fit, and they will fall out if you flip the pump's tunnel side toward the ground. For wearable pumps on a budget, this is a great combo.

I bought these because I need a second pair of momcozy kind but this is nothing compared to momcozy. Everytime I put it in my momcozyS12 it leaks :(

I am extremely disappointed was excited to try these however received them and are definitely not 17 mm also would not stay in a 12 momxozy pump

These inserts are not 17 mm. They’re more like 21 mm inserts. I’m incredibly disappointed. I could tell immediately that they were too big just by looking at them.