The Joovy Boob Breast Pump Adapter is great for moms that want to pump directly into the Boob Baby Bottle, avoiding messy transfers and additional containers to clean. The Boob Breast Pump Adapter works seamlessly with the Joovy Boob Insulator, allowing you to pump directly into the Boob Baby Bottle with out without the insulator attached. When pumping is done, you can replace the adapter with the Joovy Boob Sealing Cap, then store the bottle in the freezer. The Boob Breast Pump Adapter works with most major breast pumps, it is compatible with Medela, Lansinoh, Playtex. Evenflo, Ameda, and Simplisse (not compatible with Avent).