Harness buckle

FIG. 1 is a bottom, front, left side perspective view of a harness buckle, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a left side elevation view, with the right side being a mirror image thereof;

FIG. 5 is a rear elevation view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines depict portions of the article that form no part of the claimed design.