This OID reports the rotational speed of a fan as a percentage of its maximum RPM (0 to 100%) in the form of a signed 32-bit integer. Network engineers check this to spot fans ramping up dangerously high (indicating a thermal crisis) or slowing down too much (indicating a failing bearing). For example, a value of 100 means the fan is spinning at full speed to cool the system, while 30 means it is running at a low, quiet speed because the system is cool.