The light source is capable of sending {HEAD ~ a light} to {TAIL ~ the light} receiving means of the editing wheel 
to
The light source is capable of sending { HEAD ~ a light } to { TAIL ~ the light } receiving means of the editing wheel
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH