A magnetic float travels up and down the stem between float stops actuating or de-actuating a dry contact reed switch encapsulated inside the stem. When the magnetic field comes in close proximity to the reed switch, the contact closes.
Switch operation is determined in a dry condition with the installation fitting up and the float at rest against the lower float stop.
Normally Closed (NC): Switch will open on the rise of liquid and close on the fall of liquid.
Normally Open (NO): Switch will close on the rise of liquid and open on the fall of liquid.