Another advantage of the invention is that {HEAD ~ the glass core} can be substantially centered with {TAIL ~ respect} to the larger diameter exterior surface of the second sleeve 
substantially centered with
Another advantage of the invention is that { HEAD ~ the glass core } can be substantially centered with { TAIL ~ respect } to the larger diameter exterior surface of the second sleeve
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH