Avent classic feeding bottle 1m 1 pack the advanced two piece anti colic system helps your baby to control milk similarly to when being breastfed making classic easy to use when combining both bottle and breastfeeding the clinically proven classic two piece anti colic system is integrated into the teat making the bottle easier to assemble and clean the advanced valve on the teat opens to allow air into the bottle instead of babys tummy preventing colic the valve also fle