ThinkGeek Star Wars Death Star Kitchen Timer Officially-licensed Star Wars merchandise A ThinkGeek creation & exclusive No batteries - spring-wound mechanism - If you are not familiar with spring-wound timers, read this: YOU MUST FIRST ROTATE THIS UP TO 60 and then set it to the time you wish to count down. If you don't do this, you're not winding the timing mechanism. One minute demarcations up to 59 minutes Dimensions: 4" diameter