They are made of highly resistant medical silicone and perforated with laser which ensures that the hole is exactly the same in all of the same level, giving a precise timed flow.
The orifice is round except for that in Cereals where the hole is in Y.
They are sold in packs of 2 units in the following sizes:
Standard Teat and Wide Mouth: Level 0 (Premature)
Standard Teat and Wide Mouth: Level 1 (Newborn)
Standard Teat and Wide Mouth: Level 2 (+3 months)
Standard Teat and Wide Mouth: Level 3 (+6 months)
Standard Teat and Wide Mouth: Level 4 (For Eaters)
