The ornamental design for a cinch ring for pet harness, as shown and described.
FIG. 1 is a top, front, left perspective view of a cinch ring for pet harness showing my new design in a condition of use;
FIG. 2 is a right side elevational view thereof;
FIG. 3 is a front elevational view of the cinch ring for pet harness of FIG. 1, shown in an alternate condition for use and slightly enlarged for clarity of disclosure;
FIG. 4 is a front elevational view of the cinch ring for pet harness of FIG. 1, shown enlarged for clarity of disclosure:
FIG. 5 is a rear elevational view thereof;
FIG. 6 is a left side elevational view thereof;
FIG. 7 is a right side elevational view thereof;
FIG. 8 is a top plan view thereof; and,
FIG. 9 is a bottom plan view thereof.
The broken lines in the drawings depict environmental subject matter that forms no part of the claimed design.