Batting helmets are hard plastic hats worn over a player's normal baseball cap. While the name implies that it is worn exclusively by batters, it is actually worn by offensive players in every stage of their appearance on the field: while on deck, in the batter's box, and running the bases. Baseball helmets come in various models and sizings. Of course there are youth baseball helmets and adult baseball helmets. Some of the helmets come as one size fits all, while other models are fitted helmets.