84870211 is a DIN rail mount liquid level monitoring relay designed for filling (UP) and emptying (DOWN) applications. It features adjustable sensitivity ranging from 250 O to 1 MO, with low, standard, and high sensitivity modes, and operates within a voltage range of 0.85 to 1.10 x Un. The relay includes a 1 AgNi changeover relay output rated at 8 A AC max, with galvanic isolation via transformer (4 kV, 8 mm creepage distance) and Class II protection. Response times are 300 ms for high level and 500 ms for low level detection, with LED indicators for supply voltage and relay state. This relay is suitable for industrial liquid level control applications requiring reliable monitoring of single or dual level thresholds in tanks and reservoirs.