Mouthpiece

FIG. 1 is a top, front, and left side perspective view of a mouthpiece showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left-side elevational view thereof;

FIG. 5 is a right-side elevational view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings represent portions of the mouthpiece that form no part of the claimed design.