Features miniature size gadget 2 LEDs flash alternately can be operated pending (cord supplied) great as attention grabber ideal introduction into SMD (Surface Mounted Device) technology some extra parts are supplied, in case some get lost or damaged Specifications power supply: 3V Li button cell (e.g. CR2025 or CR2032) power consumption: 5mA approx. dimensions: Ø1.1" x 0.3" (MK141)