The Apart 19-VOL660 is a 19” unit, equipped with 6 pieces 100 volt volume controls that can handle up to 60 watts of power each. The Euroblock connectors at the back of the unit make installing very easy.The volume controls are very durable due their the step by step attenuation in 11 steps + zero position. Each volume control is equipped with a 24V priority relay. This way a microphone call will always come through at maximum volume, no matter what position the volume control is in. By using the 19-VOL660 you can adjust the loudspeaker level in different zones.