Emergency Paging Panel 1.1 microphone input, 1 line input, plus 1 fire alarm input and 1 emergency evacuation input on the panel. 2.1 AUX audio input and 1 balanced output. 3.1 alarm short trigger input, 1 24V alarm trigger input, 1 short trigger output and 1 24V alarm trigger output. 4.Independent adjustable volume for microphone and line inputs, with a master volume control. 5.Equipped with handheld microphone function, which has the highest priority. When the handheld microphone is activated, all emergency alarm outputs will be enabled. 6.The two built-in audio channels support firmware update via USB connection. 7.Supports USB function and 24V backup power supply. 8. Product Dimension: 485x300x88mm