Mask Frame

FIG. 1 is a front view of a mask frame showing my new 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 perspective view thereof; and,

FIG. 8 is an enlarged detail view of area 8 shown within FIG. 2 .

The dash-dash broken lines in the drawings depict portions of the mask frame that form no part of the claimed design. The dot-dot-dash broken lines in the drawings denote the boundaries of the enlarged detail view and form no part of the claimed design.