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