{HEAD ~ The device} includes {TAIL ~ a pair} of toroid magnets each having a north pole and a south pole 
{ HEAD ~ The device } includes { TAIL ~ a pair } of toroid magnets each having a north pole and a south pole
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH