CLINICALLY SHOWN TO REDUCE COLIC- A CLINICAL TRIAL DEMONSTRATED AT 2 WEEKS OF AGE BABIES FED WITH THE ADVENT BOTTLES EXPERIENCE LESS COLIC THAN BABIES FED WITH A CONVENTIONAL BOTTLE. SUPPORTS BREASTFEEDING - SOFT NATURALLY SHAPED NIPPLE PROMOTES PROPER LATCH-ON AND MAKES IT EASIER TO CONTINUE BREAST AND BOTTLE FEEDING. FOR HEALTHY ACTIVE FEEDING AIRFLEX VALVE WORKS WITH BABY'S NATURAL FEEDING RHYTHM WHEN BREASTFEEDING, YOUR BABY NATURALLY CONTROLS MILK FLOW. THIS IS CALLED ACTIVE FEEDING AND HELPS DEVELOP A HEALTHY FEEDING PATTERN. HOW IT WORKS THE AVENT AIRFLEX NATURAL FEEDING BOTTLE USES AN AIRFLEX VALVE WHICH WORKS WITH BABY'S NATURAL FEEDING RHYTHM. YOUR BABY CONTROLS MILK FLOW, WHICH CAN HELP REDUCE OVEREATING AND SPITTING UP. UNIQUE VALVE SYSTEM AS YOUR BABY FEEDS THE BUILT-IN AIRFLEX VALVE FLEXES TO ALLOW AIR INTO THE BOTTLE TO PREVENT VACUMM BUILD-UP. AIR BUBBLES MOVE AWAY FROM THE NIPPLE AND INTO THE BOTTLE - NOT INTO BABY'S TUMMY EXTRA SOFY SLOW FLOW SILICONE NIPPLE AVENT BOTTLE 3 PK Choose your size below. Made by Phillips