A second bubble element is mounted in the central region of the level housing, and {HEAD ~ the bubble element} is parallel to {TAIL ~ the length} of the housing 
is parallel to
A second bubble element is mounted in the central region of the level housing , and { HEAD ~ the bubble element } is parallel to { TAIL ~ the length } of the housing
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH