FIG. 1 is a perspective view of a mouthpiece showing the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is another side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is another perspective view thereof;
FIG. 9 is another perspective view thereof; and,
FIG. 10 is another perspective view thereof.
The dashed lines shown in the drawings illustrate portions of the mouthpiece that are not claimed and thus form no part of the claimed design. The shading lines shown in the drawings represent the three-dimensional contour of the claimed design and are not intended to indicate surface decoration.