From the manufacturer
NUK Simply Natural Baby Bottle
NUK Simply Natural Bottles are designed to be just like mom’s breast, giving baby a close-to-mom feel never before found from a bottle. So that you can continue that special breastfeeding bond, even when you can’t breastfeed.
Multiple nipple holes provide a natural feed, just like mom’s breast.
Nipple comes with 3 to 9 holes, depending on flow rate
9 oz bottle comes with medium flow nipple that has 6 holes
Advanced 1-piece Anti-Colic Air system helps reduce colic, gas and spit up
Super soft silicone nipple is the same shape as mom’s nursing nipple for a familiar fit