As is known, {HEAD ~ a toroid magnet} is generally doughnut shaped with {TAIL ~ a hole} in the middle; one side is north, the other south 
As is known , { HEAD ~ a toroid magnet } is generally doughnut shaped with { TAIL ~ a hole } in the middle ; one side is north , the other south
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH