{HEAD ~ A plug} is mounted on {TAIL ~ the plunger} and has axial and radial sealing surfaces 
is mounted on
{ HEAD ~ A plug } is mounted on { TAIL ~ the plunger } and has axial and radial sealing surfaces
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH