These nipples were used for my 2-month-old baby, and were used when they were a newborn. Mother's Milk Real SS x 2 Mother's Milk Consultation Room x 2 I used all four in rotation, so I think there's less wear and tear. Set of 4 silicone round nipples for baby bottles. - Quantity: Set of 4 - Material: Silicone - Shape: Round - Application: For baby bottles Thank you for looking.