Thank you @Speech & Feeding Therapist the air hole in the Olababy Training cup is an important part of the cup designe making it easier for your babies first sips. Not only is the cup beautiful it is functional with easy to read measurement windows. This is a great gift for mom and baby alike for babies first cup. #babymusthaves #newmomtips #feedingtips #firstcup #babygift #olababy