said magnets alternating in polarity so that each adjacent pair of magnets have two inside pole surfaces of {TAIL ~ respectively opposite polarities} facing said central axis, and two outside pole surfaces of respectively opposite polarities attached to {HEAD ~ said inside surface} of said case, the inside surface of said cylindrical case having a corresponding plurality of recesses, said outside pole surfaces of said plurality of magnets being positioned in said recesses, 
said magnets alternating in polarity so that each adjacent pair of magnets have two inside pole surfaces of { TAIL ~ respectively opposite polarities } facing said central axis , and two outside pole surfaces of respectively opposite polarities attached to { HEAD ~ said inside surface } of said case , the inside surface of said cylindrical case having a corresponding plurality of recesses , said outside pole surfaces of said plurality of magnets being positioned in said recesses ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH