{HEAD ~ The head holders} must hold {TAIL ~ the suction heads} against displacement or excessive deformation in the face of shocks or strains that may be exerted thereon during operation 
{ HEAD ~ The head holders } must hold { TAIL ~ the suction heads } against displacement or excessive deformation in the face of shocks or strains that may be exerted thereon during operation
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH