This kit is an extension for the Siren Kits. It adds a volume modulation to the Sound outputed by the Siren. With this kit the Volume decreases progressivly until it gets null (no sound). The time until the sound is completly stopped is the by a Potentiometer.
Unlike a classical Dub siren without this extension, the triggering is not made with the On / Off switch but with a Piezzo cell (Included).
This kit contains only one potentiometer, allowing the user to vary the decay time, wich is the time between the triggering (full volume sound), and the total stop of the sound.