Let me start by saying these replacement parts saved my pumping journey when my original Momcozy parts wore out. As an exclusive pumper, I NEED reliable replacements, and these delivered...mostly.

The Good: The diaphragms fit like a dream! They're slightly thicker than originals but create a perfect seal. I noticed zero difference in suction power - same strong pull that gets the job done. The silicone feels high quality and BPA-free (major mom win).

The Okay: Duckbill valves fit my older M9 model but started losing their tight seal after about 2 weeks of heavy use (8x/day). They still work, just not as efficiently as brand new ones. For occasional pumpers though? Probably perfect.

Pro Tip: Always keep extras! At this price point, having multiple sets means you can rotate them and always have fresh valves ready when output dips.

Cleaning is a breeze - I toss them in my steam sterilizer daily with no issues. Just remember they're NOT for the newer M9 models (learned that the hard way).

Bottom line: Not perfect, but when Momcozy's website is out of stock (again!), these are the next best thing. Stock up before your originals wear out!