and a side cut-away view, respectively, of the tubular stems of the embodiment of FIG. 13. [0036]FIG. 19 is a cross-sectional view of one female section and one male section of still another embodiment of the instant invention; [0037]FIGS. 20a and 20 b are a top view and a side cut-away view, respectively, of the magnetic ring of the embodiment of FIG. 19; [0038]FIGS. 21a and 21 b are a top view a