Replacement silicone nipplesnLevel 4 is ideal for feeding more aggressive eatersnExclusive for Dr. Brownu0026#39;s Natural Flow Standard baby bottlesnDishwasher safe top rack onlynYou will receive a total of 8 nipplesn4 nreplacement silicone nipples, exclusively for Dr. Browns Natural Flow Standard baby bottles. Ideal for feeding babies 3 months and older.