FIG. 1 is a front view of a left side strap and yoke for a mask according to an embodiment of our design;

FIG. 2 is a rear view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a front view of a right side strap and yoke for a mask according to an embodiment of our design;

FIG. 8 is a rear view thereof;

FIG. 9 is a top view thereof;

FIG. 10 is a bottom view thereof;

FIG. 11 is a right side view thereof; and,

FIG. 12 is a left side view thereof.

Where included, the use of stippling and shading is provided to show contrast in materials and/or to differentiate between different areas of the design. The claimed design is not limited to the illustrative use of stippling and/or shading.