FIG. 1 is a plan view from front; FIG. 2 is a plan view from back; FIG. 3 is a plan view from left side; FIG. 4 is a plan view from right side; FIG. 5 is a plan view from top; FIG. 6 is a plan view from bottom; FIG. 7 is an isometric view from top right; FIG. 8 is an isometric view from bottom right; FIG. 9 is a plan view from top; FIG. 10 is a cross-sectional view taken through line B-B in FIG. 9; and, FIG. 11 is a cross-sectional view taken through line A-A in FIG. 9.