Before blinking stars or hearts or guitars folks wore round blinkies at parties or bars. They wore their school colors or sports teams they liked. They wore them for safety while riding a bike. Some call them stunners. Some call them wowers. The batteries last for eight to twelve hours. To activate, twist backing clockwise until tight. To deactivate, twist backing counterclockwise. Height: 0.62 in. , 1.57 cm. Width: 0.62 in. , 1.57 cm. LED Colors: White and Blue Batteries: Includes 2 replaceable CR927 batteries.