Several tiny openings modelled on a mother’s breast give an optimal, smooth and natural flow Wide, flexible lip rest with extra-soft teat tip Innovative anti-colic vent helps prevent air being swallowed Aged 0-6 months Small Hole Teat (3 tiny openings for Breast Milk, Water, Tea), Medium Hole Teat (6 tiny openings for formula) Fits all NUK Nature Sense Baby Bottles, BPA-free, Polypropylene (PP)