NUK Nature Sense 2 Silicone Teats are teats whose silicone is extra wide and flexible that gives a feeling of natural sucking thanks to the many micro-holes instead of one. The spout allows a smooth transition from breastfeeding to independent drinking. The anti-colic valve is innovative and allows an uninterrupted feeding as in the breast and prevents swallowing air. The leak-proof tip is ideal for travelling.