Nuk first choice silicone teat is a replacement silicone teat for use with the nuk first choice bottle system size 2 for babies 6 18 monthsscientifically researched nuk orthodontic shape helps promote good digestionnew extra wide lip support helps baby to make a natural milking action and simulates breastfeeding as closely as possiblenuk developed air system allows a flow of air into the bottle through a tiny vent helping to prevent the swallowing of air thought to be a common cause of co