Let me start by saying this Nuliie flange sizing kit is a lifesaver for any pumping mom. After struggling with ill-fitting flanges from my Spectra pump, these inserts transformed my pumping experience overnight. The difference in comfort and milk output was noticeable immediately.

The 10-piece set covers all the crucial sizes (13/15/17/19/21mm), which is perfect because - surprise - nipple size can change throughout your breastfeeding journey. I love that I don't have to buy multiple expensive inserts as my needs change.

The food-grade silicone feels incredibly soft against sensitive skin. Unlike some hard plastic flanges I've tried, these don't leave me sore after sessions. The included cleaning brush and storage case make maintenance a breeze - though I do wish the case was slightly bigger to accommodate all sizes more comfortably.

A standout feature is the nipple measurement ruler. While it looks like it was repurposed from some industrial tool (the 360-degree markings are hilarious), it works perfectly for finding your ideal flange size. Pro tip: measure after pumping when your nipples are at their largest.

The only minor drawback? Some sets seem to have missing pieces based on reviews, but Nuliie's customer service appears responsive about replacements. Mine came complete, and after two months of daily use, they're holding up beautifully.

At this price point, you're getting incredible value compared to buying individual inserts from premium brands. These work flawlessly with my Spectra and even fit my friend's Elvie pump. Whether you're a new pumper or a seasoned pro, this kit takes the guesswork (and discomfort) out of flange sizing.