a plurality of {HEAD ~ magnets} attached to {TAIL ~ said inside surface} of said case at spaced circumferential locations around said inside surface, said magnets being charged so that their poles are radially aligned, 
attached to
a plurality of { HEAD ~ magnets } attached to { TAIL ~ said inside surface } of said case at spaced circumferential locations around said inside surface , said magnets being charged so that their poles are radially aligned ,
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH