Made of medical liquid silicon.Has gas-preventing Anti-colic system. Slow flow (Nr:1) is for 0-5 months, ordinary flow(Nr:2) is for 5-12 months and fast flow (Nr:3) is suitable for 12-18 months babies to feed. According to nipples for standard feeding bottles there are orthodontic and classic (rounded) shapes are also available. There are also mother breast nipple-like teat have been designed for wide-neck feeding bottles.