here are the avent caps/discs:

http://www.amazon.com/Philips-AVENT-Classic-Bottle-Sealing/dp/B000067QMD/ref=sr_1_2?ie=UTF8&qid=1412301951&sr=8-2&keywords=Avent+bottle+caps

basically you put the grey ring on the bottle, pop this disc/cap thingy into the white bigger ring and screw that on, and it creates a nicer seal then you'd otherwise get then if you put the clear lid directly on the white bigger ring thing. Helpful if you're going to refridgerate your milk and also dont want to have to own a million nipples.

Also FYI the lansinoh Momma nipples fit on the avent bottles. DS would not use the avent nipples, and the lansinoh momma bottles are a disaster but the momma nipples are really nice. so we just combined the two.

Before you buy a lot of bottles with this pump in mind, make sure you like it and it actually works for you. I think the ameda purely yours is a POS compared to other pumps. I don't think I'm the only one as there have been other threads on this. I would search and link for you but I can't easily do it from my phone.

I pumped directly into Dr. Brown's bottles for over a year from Ameda pumps. (I used a Platinum most of the time, but the godawful Purely Yours occasionally, too.) It was so much easier than pumping into bags and dealing with that hassle! Just pumped straight into the bottles that we used to feed him.

Thanks PPs. What are the snap in bottle caps?

Playtex also makes a pump adapter. Hard to find tho. I think it now comes as part of a bottle set.

The Avent adapter saved my sanity. Get the snap-in bottle caps as well.

anyone one know if comotomo's fit?

Dr brown's and evenflo fit , too.

My pump came with a few Ameda bottles, and my old Medela bottles fit onto it fine as well. They're a standard neck size.

You can buy adapters. I bought adapters for the avent bottles and they worked well. Check amazon.

Which bottles fit directly into the ameda purely yours pump (if thats even possible). I'm looking to pump directly into a bottle. Thanks!