The front cover is movably mounted on the base and has a rear surface and {HEAD ~ a transverse slot} formed on {TAIL ~ the rear surface} 
formed on
The front cover is movably mounted on the base and has a rear surface and { HEAD ~ a transverse slot } formed on { TAIL ~ the rear surface }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL