All new Selmer saxophone necks are created based on the Jubilee Series design. This new design features many improvements over the older models. The new Jubilee necks have improved response and resonance due to the lighter weight key mechanism and mounting system. Selmer removed the "guide" that used to be attached to the tube near the octave pip. The neck tenon itself has not been changed much and these necks will fit non-Jubilee Selmer saxophones.