New Tech Junkies NTJ Bracelet LED Flashing W/Sound & Motion 2 1/8" Diameter for Parties, Weddings Imported Sound & motion activated flashing lights inside. (fits kids and most small wrist adults) On/off switch for lasting battery life. Removable and replaceable batteries (batteries included). Very sensitive sensor for sound and music. Full 60 day warranty from (New Tech Junkies).