Philips AVENT Breast Pump Conversion Kit (761269002456)
Now you can use the same bottle to collect, freeze, heat, and feed breast milk. This new and improved conversion kit now offers you the choice to use Avent's reusable bottles or disposable bottles, or...
Pros: Adapts to almost any pump, Great value, can pump into all Avent bottles/cups.
Cons: Must buy two kits if you use a double pump.