When the magnet is parallel to the reed switch three lobes are generated showing magnetic sensitivity arrays. Two are on the sides of the switch and one is centered over the gap of the reed switch. Each lobe shows a solid line which indicates where the contacts will close once the magnet crosses that boundary. The drop-out or contacts opening will occur when the magnet is withdrawn passing over the dotted lines. Since the lines of force of a magnet are invisible to the eye, these lines represent the boundaries where the pull-in or reed switch closure and drop-out or reed contact opening occurs. The same result would occur if the reed switch was moved relative to a stationary magnet. Reversing the polarity of the magnet will have no effect on the three magnetic sensitivity lobes.