They are the only pacifier that takes our son and so no longer sucking his thumb. I buy the 0-3 month version although he is already 15 months old, there are different other versions are not in size, but only in the degree of hardness and in my opinion are too hard. A disadvantage of this model is that the round parts everywhere underneath roll! 4 stars they got, because my son neither Mam, still Avent, Nuk still took, but always his thumb and now it takes place Thumb this pacifier here!