I bought this mug for my daughter, in order to prepare for weaning. The valve, very flexible, which is designed to reproduce the natural suckling babies, is the same material as the baby bottle nipples. So the transition to the cup is more gradual. I have purchased another and we no longer used bottles! There is a cap which is very convenient to go on walks. My daughter now uses cups with spouts are harder to drink water during the day. But she still likes to drink his milk in this cup. Be careful, the cup is wide enough, it does not fit in some bottle warmers, as Beaba. Excelling product I recommend.
