Principle
Simple theory as liquid buoyancy is utilized for the main principle of this “FF” series. A change of liquid level correspondingly travels the float to extreme levels up and down. The reed switch is thus “NC” and “NO” exchanged as well as the permanent magnet on pivot will have mutual repellence to the other one inside on the housing for like poles, which the Microswitch is button-pushed by magnet to states “NO” and “NC” exchanging likewise.