Mask Frame

FIG. 1 is a top front perspective view of a mask frame showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a right side view thereof.

The dash-dash broken lines depict portions of the mask frame that form no part of the claimed design. The dot-dash broken lines depict the boundaries of the claimed design and form no part thereof.