A guide 1, wherein said housing unfolds to facilitate {HEAD ~ installation} onto {TAIL ~ said track} at any point along the length of said track 
onto
A guide 1 , wherein said housing unfolds to facilitate { HEAD ~ installation } onto { TAIL ~ said track } at any point along the length of said track
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH