The easy approach to controlling noise levels in the classroom, library or corridors, and also as a visual signal for hearing impaired etc. This highly visual traffic light system allows quick response either using the lights or combined with the siren. As noise levels increase, lights change from green (acceptable), to amber (noise level rising) to red (too noisy). The adjustable sound level meter enables noise levels to be set from 50dB up to 110dB. The unit is mains powered and can be wall or table mounted.