Contains red and green alarm lights and buzzer with "squelch" button. Green light remains illuminated while "service" bank is in use. When "service" bank is exhausted, green light is extinguished, red light plus buzzer, rated 75 decibels within 100 cm, is activated to ensure notice of the alarm conditions. A touch of the squelch button silences the buzzer, but the red alarm light will remain illuminated until the exhausted bank has been replaced.