Why does my Philips Avent Natural Bottle cap have holes in it?

The cap still offers significant protection from external particles and keeps the teat clean and safe.
We are committed to complying with the highest safety and quality standards in all of our products.

If you still have the older version of Avent bottle and cap, without the ventilation holes, it is still safe to use. 

To ensure safety and effectiveness, follow the usage and maintenance instructions provided in the user manual and keep the unused bottle parts out of the reach of children.