My son is 15 months old, wears 18 month old size clothes, and I could not begin to fit his head through this.  The hat is tiny and much too small to fit his head, it sits on the back of his head like a beanie.  Definitely not for the 2-4T it claims to be for.  I attempted unsuccessfully to return it, so I ended up cutting slits in the neckhole all the way down the collar on both side for his head to fit through.  He wore it and people could identify what he was supposed to be, but I was rather disappointed.