Now your baby can transition from breast to bottle in a natural way with the NUK Simply Natural Glass Bottle. Made of odor- and stain-resistant glass, each wide-neck bottle has an orthodontic nipple with multiple feeding holes, making it most similar to mom’s breastfeeding nipple. Glass bottles feature an advanced one-piece Anti-Colic Air Vent that helps reduce colic, gas, and spit-up. For a comfortable feeding every time, the air vent should be under baby’s nose with nipple holes on top. The Simply Natural glass bottle works with all nipples, caps, and collars from the Simply Natural line. Glass bottle is easy to clean, BPA-free, and dishwasher safe.