Let me start by saying this kit solved my flange-size struggles overnight. As someone who used to dread pumping sessions due to discomfort, these inserts made a dramatic difference. The soft silicone molds perfectly to my Spectra pump, eliminating that awful 'tugging' sensation I used to get with standard flanges.

The variety of sizes (13mm-21mm) is genius - my nipples actually changed size postpartum, and being able to swap inserts was a lifesaver. Pro tip: Use the included measurement ruler after pumping when your nipples are most swollen for the most accurate fit.

What surprised me most was the milk output improvement. With proper sizing, I went from getting 2oz per session to nearly 3.5oz! The food-grade silicone feels premium (no weird smells) and the cleaning brush included is perfect for getting into those tiny crevices.

Two minor gripes: The storage case feels flimsy, and I wish they offered a 'refill pack' option for your preferred size rather than repurchasing the whole kit. That said, at this price point with 10 inserts, it's still cheaper than buying individual flanges from big brands.

After 3 months of daily use (washed after every session), my preferred 17mm insert shows no signs of wear. For moms unsure about sizing or using multiple pump brands, this is absolutely worth trying before investing in expensive custom flanges.