JVA LOW VOLTAGE 4 Zone monitorThe ZLM4 is a 4 zone, low voltage, electric fence monitor. The ZLM4 may be used by itself or in conjunction with a number of high voltage security electric fence energizers. The ZLM4 monitors up to 4 loops of fence wire, each up to several hundred meters long, to detect someone tampering with the fence by cutting or shorting the wires. When used in conjunction with a high voltage electric fence energizer, the ZLM4 is wired to the non energized earth