The Omron 61F-G3 is a plug-in, floatless level controller designed for single or two-point liquid level control. It is widely used for automatic water supply and drainage operations in industrial facilities, buildings, and water treatment plants. By using the conductive properties of the liquid, it provides a reliable and maintenance-free solution for monitoring levels in tanks, reservoirs, and sumps. Its compact, plug-in design allows for easy installation and replacement, making it a popular choice for controlling pumps and valves to maintain desired liquid levels.