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