In {HEAD ~ this embodiment}, the bottom wall 154 is also wider than the top wall 152 to facilitate attachment of {TAIL ~ the coil restraints} to the trough 
In { HEAD ~ this embodiment } , the bottom wall 154 is also wider than the top wall 152 to facilitate attachment of { TAIL ~ the coil restraints } to the trough
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH