The philips avent airflex variable flow teat has a soft wide shape which encourages your baby to open the mouth wide when feeding and to literally latch on to the teat he or she can then suckle using the same movements of their tongue and jaw as they do when breastfeeding the airflex teat your baby controls milk flow more like breastfeeding which can help reduce overeating and spit up a unique skirt system flexes to allow air into the bottle and promotes healthy active feeding and reduc