A magnetic module with two front anchoring surfaces magnetically activatable and deactivatable by inversion of the magnetic flux; the module comprises a first and a second fixed magnetic core, each one configured with a plurality of polar elements defining a respective front anchoring surface, and a rear surface, as well as provided with a first plurality of permanent magnets arranged between contiguous polar elements, wherein homonymous poles (N, S) of the permanent magnets are in contact with lateral faces of the single polar elements, to generate alternatively induced poles of opposite polarity in each fixed magnetic core. A movable magnetic unit for an inversion of the magnetic flux is disposed between the two fixed magnetic cores, and it is configured with a second plurality of permanent magnets having poles (N, S) alternatively of opposite polarities facing the rear surface of the two fixed magnetic cores; the movable magnetic unit can be moved between a first and a second operative position for the inversion of the magnetic flux, to magnetically activate and respectively deactivate one or both the front surfaces of the anchoring module.