the third optical beam pointer further includes {HEAD ~ a optical element} for converting the third horizontal beam into a fourth vertical beam spreading vertically by rotating spread directions of the third horizontal beam by {TAIL ~ 90°}, and 
the third optical beam pointer further includes { HEAD ~ a optical element } for converting the third horizontal beam into a fourth vertical beam spreading vertically by rotating spread directions of the third horizontal beam by { TAIL ~ 90 ° } , and
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH