Designed for Longer, Safer Breastmilk Storage. For Storage of Breastmilk in Refrigerator or Freezer. Express Milk Directly Into Bottles. Specially Designed Sealing Disk Prevents Storage Bottle from Leaking. Containers are Freezer-Safe & Dishwasher-Safe. Standard Sized Neck. BPA Free Designed exclusively for use with the Lansinoh® Affinity™ Double Electric Breast Pump. You can pump directly into these BPA-free bottles so you can use the same container for storing and feeding without ever transferring your milk.