{HEAD ~ the third light projecting portion} is adapted to project {TAIL ~ the third visible light beam} traveling vertically in the shape of a cross consisting of a traversal beam spreading along the line connecting the first optical beam pointer and the second optical beam pointer, and a longitudinal beam spreading perpendicular to the traversal beam, 
{ HEAD ~ the third light projecting portion } is adapted to project { TAIL ~ the third visible light beam } traveling vertically in the shape of a cross consisting of a traversal beam spreading along the line connecting the first optical beam pointer and the second optical beam pointer , and a longitudinal beam spreading perpendicular to the traversal beam ,
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH