The arrays of {TAIL ~ permanent magnets} each have north and south poles distributed in both longitudinal and latitudinal directions along {HEAD ~ a plane} 
The arrays of { TAIL ~ permanent magnets } each have north and south poles distributed in both longitudinal and latitudinal directions along { HEAD ~ a plane }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD