G2G's silicone nipples are made from a transparent, medical grade silicone that is heat-resistant, non-toxic, and odorless. The nipples are free of nitrosamines, a potentially harmful contaminant found in many rubber nipples. * 3 nipples per package; * 3 speeds to choose from: Beginner (slow flow, 0-3 months), Intermediate (medium flow, 3-6 months), Expert (fast flow, 6+ months); * Dishwasher safe.