The Wide-Neck Storage / Travel Caps are accessories designed specifically for Dr. Brown's Natural Flow Baby Bottles. These caps securely seal the Dr. Brown's Natural Flow Baby Bottle for travel and storage of formula or breast milk.
These are a lifesaver as shaking the bottles without them would leave a leaky mess! This was the only place I found the storage caps for the WIDE vent bottles...seems like they are no longer made! Very happy with the fast shipping from this company!! :)