FIG. 1 is a left front perspective view of a water filter key showing a first embodiment of our new design;
FIG. 2 is a front view of the water filter key of FIG. 1;
FIG. 3 is a bottom view of the water filter key of FIG. 1;
FIG. 4 is a left front perspective view of a water filter key showing a second embodiment of our new design;
FIG. 5 is a front view of the water filter key of FIG. 4;
FIG. 6 is a bottom view of the water filter key of FIG. 4;
FIG. 7 is a left front perspective view of a water filter key showing a third embodiment of our new design;
FIG. 8 is a front view of the water filter key of FIG. 7;
FIG. 9 is a bottom view of the water filter key of FIG. 7;
FIG. 10 is a left front perspective view of a water filter key showing a fourth embodiment of our new design;
FIG. 11 is a front view of the water filter key of FIG. 10;
FIG. 12 is a bottom view of the water filter key of FIG. 10;
FIG. 13 is a left front perspective view of a water filter key showing a fifth embodiment of our new design;
FIG. 14 is a front view of the water filter key of FIG. 13;
FIG. 15 is a bottom view of the water filter key of FIG. 13;
FIG. 16 is a left front perspective view of a water filter key showing a sixth embodiment of our new design;
FIG. 17 is a front view of the water filter key of FIG. 16; and,
FIG. 18 is a bottom view of the water filter key of FIG. 16.
The broken lines shown in the drawings illustrate portions of the water filter key and environment that form no part of the claimed design. The water filter key is shown with a symbolic break in its length. The appearance of any portion of the water filter key between the break lines forms no part of the claimed design.