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