RVI volume controls series is made up of a control circuit with 11 positions switch (10 + off) and a transformer, in order to be used in 70-100V systems. It can be used to set the volume of one or more constant voltage speakers. Available in 3 versions: 30W, 60W or 100W. Thanks to the on board relay (enabled through a 24Vcc control), the volume control can be bypassed and forcibly brought to the maximum volume in case of priority announcements. Set for box 503 mounting.