One size fits all- adjustable, suitable for women & men, Boys & Girls ect.Light up brim , Lighting methods: Constant on/Quick flashing/Off.Easy "on/off "switch concealed in the brim, CR2016 lithium battery replaceable, continuous use up to 72 hours. (battery replacement). Material: cotton.Best enjoyed and viewed in a low light or dark environment and can be avoid some potential traffic dangersIt can be widely used in Night club, Disco, KTV, Bar, Banquet, Party, Floor show, Stage show, Evening show, Performance show, Vocal concert, Carnival, Wedding dinner, Lounge, Cafe, variety of fashion shows & Nightly entertainments and some other Special Events. Let you become a eye catcher!!! ​​