·DC9-16V 6 OHM Effective Emergency Siren System CJB300-S6301·Heavy duty, delicate, high technology; ·Features with MIC, 7 basic siren tones, 10 horns and function of two different tones mixing from two speaker channels; ·300W to 600W hight power output; ·Micro-control circuit to provide stable performance; ·Built-in protection against over voltage, short circuit or reverse polarity; ·Dimmable LED backlighting for controller; ·Three light control buttons; ·Horn output independently connected to vehicle steer, convenient for driver to operate horn tone when needed;.