A float level switch is used to determine a liquid water level. Typically you will use them for fill/stop sensors. You can also use several to determine intermittent water levels of a single container. This is why there is a
percent option to correlate the sensor with a liquid level it represents.
The float sensor will return a reading of 0 or 1. Based on your circuit setup this could mean the liquid level is now at the set level or past it.
[Boolean] 0 or 1