Abstract: An elongated, inverted and generally L-shaped tubular body is provided including generally right angularly disposed horizontal and vertical tube sections intersecting at one pair of ends thereof. The lower end of the vertical tube section includes a diametrically reduced terminal end beveled toward the upper end of the vertical tube section on the side thereof remote from the vertical tube section side from which the horizontal tube section projects and the horizontal tube section includes an enlarged abutment flange thereon intermediate the opposite ends thereof.