Stopper cylinder

FIG. 1 shows a front view of a stopper cylinder showing my new design;

FIG. 2 shows a rear view thereof;

FIG. 3 shows a right side view thereof;

FIG. 4 shows a left side view thereof;

FIG. 5 shows a top view thereof;

FIG. 6 shows a bottom view thereof;

FIG. 7 shows a bottom, front and left side perspective view thereof;

FIG. 8 shows a bottom, rear and left side perspective view thereof;.

FIG. 9 shows a top, rear and left side perspective view thereof; and,

FIG. 10 shows a top, front and left side perspective view thereof.

The broken lines in the drawings depict unclaimed environmental subject matter.