Students can use the sound to light minikit for different and fun applications because the four LEDs light up simultaneously to every sound within its range. Use it as a door bell or telephone indicator or just watch it flash to the sound of music. This minikit is easy to build and includes an onboard microphone. Dimensions: 1½" × 2¼" × 1½". A soldering iron, solder and 9 V battery are required and available separately.