The Nuk® Pacifier'S Unique Breast-Like Nipple Is Shaped To Soothe Baby Just Like Mom. This Makes For An Easy Transition From Breast To Pacifier And Back. Invented Over 60 Years Ago By Pediatric Dentists And Doctors, Nuk®'S Unique Orthodontic Nipple Shape Helps Promote Healthy Oral Development. Size: From 0 To 6 Months