A magnetically actuated apparatus, which enlarges, extends and makes continuous magnetic fields used by magnetically controlled devices, such as a magnetic reed switch for use in physical security monitoring systems is shown. Apparatus includes a sensor and a magnetic actuator for use with a movable closure member. The sensor is mounted into to a fixed support member that is arranged for displacement relative to a second movable support member. The sensor has a pair of contacts that are connectable to an electronic circuit. The contacts form a switch that is actuated by the magnetic actuator. The magnetic actuator comprises a unique elongated magnet with specific polarity or a plurality of aligned, alike permanent magnets that are mountable to the second support member. The aligned magnets have like magnetic fields that align one another and combine to form an effective magnetic actuation field that has a given magnitude and a given direction that is greater that the magnitude and direction than any one of the magnets. The elongated magnet has a specific pole for a given distance as its controlling means. The effective magnetic actuation field increases the distance in which the movable support member is displaceable relative to the fixed support member without changing the electric condition of the sensor. The present invention creates a magnetic apparatus, having a wider and controllable gap and break point distance not found in the present art.