Refrigerator Filter

FIG. 1 is a top-front perspective view of a refrigerator filter. FIG. 2 is a front view of the refrigerator filter. FIG. 3 is a rear view of the refrigerator filter. FIG. 4 is a left view of the refrigerator filter. FIG. 5 is a right view of the refrigerator filter. FIG. 6 is a top view of the refrigerator filter; and, FIG. 7 is a bottom view of the refrigerator filter. The broken lines shown in the drawings illustrate portions of the article and form no part of the claimed design.