(1) The Red brass sax manufacturer tells you that first take the reed out of the whistle clip or the whistle box, align the reed plane with the mouthpiece plane, align the top of the reed with the top of the mouthpiece, and hold the whistle with the thumb of the left hand. The tablet is pressed on the mouthpiece.

(2) The Red brass sax manufacturer tells you that after that, put the whistle hoop on the flute with the right hand, the upper edge of the whistle hoop should cross the mouthpiece indication line, and then align the stitching line of the whistle hoop with the center of the reed.
(3) The Red brass sax manufacturer tells you that after installing the reed, insert the mouthpiece into the neck tube, and align the center of the mouthpiece tuyere with the harmonic key on the neck tube. Insert the installed neck tube into the main tube, then tighten the screw on the upper end of the main tube.
(4) The Red brass sax manufacturer tells you that before the ensemble, the standard tone A is generally used for tuning, the alto sax is played with F sharpened, and the tenor played B. If the saxophone pitch is low, insert the mouthpiece into the cork of the neck tube more; if the saxophone pitch is high, pull the mouthpiece outward from the cork of the neck tube until the pitch is accurate.
The above is the Red brass sax manufacturer's introduction and analysis of the installation of the sax, hope it helps you.