... temp:-20~+125 4.Certificates: CE, RoHS,FDA Level Switch Characters:1.Low cost: cheap material2.long ... ball moves along the stem with the water level, the magnet inside the ball will cause the ... circuit, this will send the control board a signal that the liquid level is at the predetermined position, ... , air-cooler, BSD-P, humidifier, dehumidifier,fluid control,a pump,an indicator,an alarm,or other device. ...