All Dr. Brown's teats are super-soft and made of high-grade silicone. This teat is available for the Standard Narrow Neck and Wide Neck Dr Browns Natural Flow baby bottle. All Dr Browns silicone teats are precision cut to work in conjunction with the internal vent system. Teat suitability: level 1: newborns + level 2: 3 months + level 3: 6 months + level 4: 9 months +