In {HEAD ~ an equally effective embodiment} the single bead filler extends radially outward beyond the radial extent of {TAIL ~ the outer filler strip} 
In { HEAD ~ an equally effective embodiment } the single bead filler extends radially outward beyond the radial extent of { TAIL ~ the outer filler strip }
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL