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 Chad Delgado

Only used for a few feedings so I can't speak to their longevity, but so far they're great!I use a Spectra pump but prefer to feed out of Avent glass bottles for a variety of reasons. It drove me completely nuts that despite the bottles having the same exact diameter, the bottle collars were not compatible and caused leaking. My husband is (understandably) frustrated by complex systems and so I was absolutely thrilled that this brand somehow managed to make a bottle collar that is compatible and non leaking with both Spectra and Avent Glass bottle!I've written on the white sealing discs with dry erase marker and had no issues, I just wipe it off with my finger before washing.I haven't subjected them to any extreme tests, but just holding upside down with a little shaking did not produce any leaks for me, provided the lid was screwed tight. I have also not had the problem others reported of bottles unscrewing from their pump, but I will update my review if it occurs.Short version: great cheap additional bottle option, compatible with Spectra pump, lids compatible with Spectra bottles, Avent glass, Evenflo nipples, and Lansinoh Naturalwave nipples. Everything I needed!