With a special integrated valve for venting, these nipples reduce colic symptoms by reducing air intake while the baby nurses. These nipples are made of 100% food grade Silicone and do not contain PVC or nitrosamines. Replacement nipples come two per pack, in the following stages:-
Stage 1 (0-3 months)
Stage 2 (4-8 months)
Stage 3 (9+ months)