The latching sensor is similar to the latching reed relay. A permanent magnet will also be used that is partially magnetized such that the contacts come closer together but still remain in the open state. Bringing a magnet into the influence of the latching reed sensor with an aiding field to the existing permanent magnet inside the sensor will cause the reed contacts to close and remain so once the second magnet is removed. Applying a second magnet again, but with its field reversed will apply an opposing magnetic field to the latching reed sensor, which in-turn opens the contacts. The contacts will remain in the open state once this second magnet with reversed magnetic field is removed.