This consists of a spring (2.1) that raises or descends an turning the screw (2.2), which becomes endless to move the riveted nut (2.3) that, in turn, serves as a closure of the spring. On the point of the screw and the base of the spring two dampers (2.4 and 2.5) are fastened in such a way they permit the mouthpiece and reed of the wind instruments of the clarinet and saxophone families to be secured between both elements, touching the dampers only to avoid the transmission of vibrations to the set, thus reducing the contact surface with the results that the same set is valid for any instrument. Possible changes in the shape and material of the spring (2.1) and the dampers (2.4 and 2.5) have been envisaged so that the way of tightening, the position and contact surface with the reed and mouthpiece can be varied.