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