<p>Hand held adjustable device comprising: a grip (2) provided with an end portion (5); a plurality of needles (7) which extend axially from the end portion (5) and are made of electrically conductive material, and a device for adjusting (10) the insertion depth of the needles in a tissue in which a cup-shaped body (12) borne by said end portion (5) of the grip is provided with an end wall (13) having holes (14) for the passage of said needles (7). A system for adjustment of the relative position between the cup-shaped body (12) and the end portion (5) provides an axial sliding of the cup-shaped body (12) with respect to the end portion (5) to adjust the length of the portion of the needles (7) protruding from said end wall (13) and therefore the insertion depth in the tissue.</p>
