Retaining Ring

FIG. 1 is a front, left perspective view of a retaining ring, showing my new design; FIG. 2 is a back, right perspective view thereof; FIG. 3 is a front elevational view thereof; FIG. 4 is a back elevational view thereof; FIG. 5 is a left side view thereof; FIG. 6 is a right side view thereof; FIG. 7 is a top plan view thereof; and, FIG. 8 is a bottom plan view thereof.