JVA ZM50 - 50 Sector Monitor* Excluding Battery and Power Supply The JVA ZM50 is an advanced security electric fence monitoring system, enabling the partitioning of an electric security fence into 50 programmable sectors. This gives greater accuracy in detecting the locality of a fault on the fence line which in turn allows for quicker targeted responses and or better camera positioning. The system is ideal when energizer placement in the field is not always possible. An