Mask

FIG. 1 is a rear view of a first embodiment of a mask showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a bottom perspective view thereof;

FIG. 8 is a rear view of a second embodiment of a mask showing my new design;

FIG. 9 is a front view thereof;

FIG. 10 is a bottom view thereof;

FIG. 11 is a top view thereof;

FIG. 12 is a left side view thereof;

FIG. 13 is a right side view thereof;

FIG. 14 is a bottom perspective view thereof;

FIG. 15 is a rear view of a third embodiment of a mask showing my new design;

FIG. 16 is a front view thereof;

FIG. 17 is a bottom view thereof;

FIG. 18 is a top view thereof;

FIG. 19 is a left side view thereof;

FIG. 20 is a right side view thereof; and,

FIG. 21 is a bottom perspective view thereof.

The broken lines depict portions of the mask that form no part of the claimed design.