Paced Feeding: With A Patented Air-Vent System, Calma Ensures Milk Flows Only When Vacuum Is Created, Allowing Your Baby To Drink, Pause, And Breathe At Its Own Pace10One Size Fits All Ages: The Milk Flow Is Automatically Regulated By The Strength Of The Vacuum Applied, Eliminating The Need To Adjust Nipple Flow Rates As Your Baby Grows10Compatible With Medela Bottles: Collect, Store, And Feed Using Medela Bottles. The Included Multi-Lid Prevents Any Milk From Spilling During Transportation10Clean And Store: All Components Of The Calma Nipple Fit In The Dishwasher (Top Rack), And Once Cleaned, They Can Be Stored Using The Multi-Lid And Cap Provided10Made In Switzerland And Made Without Bpa