These Bell Shaped Brass Lure Bodies are hollowed out inside, allowing the use of brass or plastic beads to be placed inside to create a "ringing" sound.  This body is extremely popular on weighted spinner applications but have been gaining momentum on trolling spinners as they get experimented with.  There will soon be a section in my Spinner Dave's Tips, Tactics, News and Views with some suggestions on how to use these bodies.  Keep an eye out...