The space provided between brush members 4 a and 4 b allows {HEAD ~ a mounting strip} to be included in {TAIL ~ the housing} 
to be included in
The space provided between brush members 4 a and 4 b allows { HEAD ~ a mounting strip } to be included in { TAIL ~ the housing }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL