The cross-cut is especially designed to respond to baby's sucking strength and will provide

All nipples are made of food grade liquid silicone, which is heat-resistant, non-toxic, non-sticky, odorless, Nitrosamine free and complies with the FDA.

The special vent design not only prevents the nipple from collapsing but also avoid baby from swallowing excess air, which may cause colic and hiccough during feeding.