Filter frame

FIG. 1 is a perspective view showing the new design for an filter frame;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The fine dash-dash broken lines in the filter frame of FIGS. 1-7 depict environmental subject matter that forms no part of the claimed design. The thicker dash-dash broken lines define boundaries of the claimed design and form no part thereof.