An integral and absolutely essential part of the saxophone is the sleeve and the tenon. Through this connection, vibrations are transmitted from the mouth through the neck to the saxophone. With virtually every old instrument, this part is deformed in some way or simply leaking. In this case, it is the same as if the octave key does not seal. The instrument seems to play, but much worse. It should be mentioned that in many saxophones, especially the American Conn, Holton,…, but also the French SML, the tenon are conical from the inside, which from a practical point of view makes it impossible to expand the pin and fit it with the sleeve. Another case is that the wall of the tenon is so thick that it cannot be spread evenly, for example with AMATI saxophones. In these cases, nothing remains but to produce both new components. In cooperation with the company ReKov.cz, I can offer the assembly of both parts accurate to 0.001 mm thanks to CNC machining. In the final form, just lightly tighten the screw and the instrument is ready to play.