Permits Dribble-free Drinking Without The Need To Sit Up Or Raise The Head Placing A Finger Over The Vent Hole In The Cap Controls The Flow Of Liquid Through The Mouthpiece The Design Reduces The Amount Of Spilled Liquid Should A Mishap Occur The Opening In The Mouthpiece Is Large Enough For A Straw Graduated At 4 6 And 8 Oz Levels Dishwasher And Autoclave Safe