The cable holder has two side walls and {TAIL ~ a bottom wall}, with grooves at {HEAD ~ the tops} of the side walls 
The cable holder has two side walls and { TAIL ~ a bottom wall } , with grooves at { HEAD ~ the tops } of the side walls
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH