Comotomo baby bottles are deisgned to most closely mimic breastfeeding to reduce bottle rejection and nipple confusion issues;Ultra wide-neck design allows easy cleaning by hand without a brush;Safe in microwave, boiling water, dishwashers and sterilizers;Nipple and body is made of 100% safe hygienic medical grade silicone;Dual anti-colic vents prevent unwanted air-intake and reduce colic