{HEAD ~ The coils} are in the form of {TAIL ~ spirals} and extend in a predetermined direction 
{ HEAD ~ The coils } are in the form of { TAIL ~ spirals } and extend in a predetermined direction
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH