Review on Maymom Wide-Mouth Milk Storage Collection Bottle With SureSeal Sealing Disk; Compatible With Spectra/Motif Luna/Ameda MYA/Bellababy Pumps. Can Replace Spectra S1 S2 Bottles, 6 Pc (4.7Oz/140ML, 6Pc) by Todd Adams

Honestly, it's impressive that Maymom has built a small empire by creating pump parts that exceed the quality of the original parts. Not only do they make a wide range of flange sizes (SUPER important for pumping) and quality parts at a fraction of the price of the name brand, they actually improve upon the original parts.These bottles are superior to the Spectra bottles I have for two reasons. One, they HAVE MEASUREMENTS. It's so annoying to weigh my bottles on a kitchen scale because the Spectra bottles don't have measurement lines. Thank goodness these have markings to the quarter ounce! And two, Maymom included two O-rings. Just a few days before my Maymom bottles arrived, I had a bottle drop from my Spectra mid-pump which resulted in a small breakdown with lots and lots of tears. I opened this box of bottles and saw a small bag at the bottom with the O-rings and a card explaining that this is not uncommon with Spectra parts since they don't always lock tight together, and the O-rings will help to prevent bottles falling. I was SO excited! Of course, now I'm using my Maymom flanges with my Maymom bottles, so I haven't had that issue because they lock perfectly together. But if I use the Spectra or Avent bottles again, I'll be using the O-rings for sure!