Thanks to the revolutionary intui-flow system, it adapts to the needs of every baby and offers a feeling like a mother's breast. The Physio nipple fits all Chicco PERFECT 5, WELL-BEING and ORIGINAL TOUCH bottles. When used with the PERFECT 5 bottle, the bottle breathes through the base, leaving air through the balancing membrane valve. When the nipple is placed in a WELL-BEING and ORIGINAL TOUCH bottle, the anti-colic valve at the nipple base prevents the nipple from receding and swallows air, helping to prevent colic, regression and ensure a smooth, loose breast. Compatible with sterilizer. Machine washable Read the instruction manual 0% BPA in accordance with applicable law Chicco Physio Silicone Baby Bottle Nipple is made of hygienic silicone and has an anti-colic valve. The hygienic silicone nipple allows the baby to breastfeed calmly, thanks to its large shape that makes breastfeeding more natural. The package includes 2 pieces.