This Harmony Control, LA9 measurement probe is an accessory for control relay. It allows monitoring of liquid level. It is compatible with control relay RM84, RM4L, and RM35LM. This measurement probe is an accessory for control relay, ideal for monitoring of liquid level. It applies to a wide type of industrial automation applications. It also offers integral LED for indicating control status and it is designed to be temperature up to 100 °C. It is compatible with control relay RM84, RM4L, and RM35LM. It provides automatic detection of abnormal electrical values before they incur serious damage to machinery, this helps to reduce your maintenance and downtime costs.