Velleman MK103 Sound-to-Light UnitVelleman Mini Kits to chenge sound to light Level 2 Kit, very easy to assemble VEL MK103, MK103RS,made in EU can be used to indicate the telephone, door bell. Practical applications, Great for music Sound Activated LEDs Kit Four high intensity LEDs light up and react simultaneously to every sound. Use for different, fun, and practical applications like a sound indicator or simple sound to light unit for music. The unit can also be used Product