FIG. 1 is a perspective view of a sprinkler; FIG. 2 is a front elevation of the sprinkler; FIG. 3 is a rear elevation of the sprinkler; FIG. 4 is a left side elevation of the sprinkler; FIG. 5 is a right side elevation of the sprinkler; FIG. 6 is a top plan of the sprinkler; and, FIG. 7 is a bottom plan of the sprinkler.