Available in various hole size (Medium, Large, Extra-Large &amp; X-cut). <br>Made of non-toxic food-grade quality silicone rubber <br>Soft resilient and non callapsible during feeding. <br>All nipples can be reserved for comprehensive cleaning and can fit nicely into any standard feeding bottles. <br>Special anti-colic valves helps to prevent gas build-ups and stomach discomfort. <br>Sterilize before and after each use. <br>Comply to British Standard 7368. <br>Comply to EN 71-3.