Abstract: Pick-up plug comprising at least an annular stator (10) engaging driving means, a motor (11) in an equally annular shape capable of being associated to said stator (10) and having the same axis (O) thereof, said rotor and said respective stator (10) being mutually engaged by means of generally known means and being adapted to rotate relatively to each other about said common axis (O). In the stator there are applied a plurality of magnets adapted to be collected into a multiplicity of distinct clusters, in which each cluster of magnets comprises magnets provided with a same polarity ((N), (8)), and in the rotor there are applied a plurality of magnets capable of being collected into clusters in a similar manner. Said magnets of the rotor and said magnets of the stator are arranged so as to enable said rotor and said stator to dispose themselves, when at rest, into a defined number of prefixable positions.