3M Speedglas G5-01 Directives D'utilisation page 31

d. There is an outline of the hinge etched on the inside of the welding shield. One arm of the etching is shorter than the other. The long arm of
the hinge attaches to the pivot ring and the short arm of the hinge attaches to the outer welding shield post. When installed correctly, the
hinge will fall exactly into the etched drawing on the outer welding shield (Fig. 26c).
Fig. 26b
Fig. 26c
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