a cover trim member for engagement with the housing for enclosing the cavity when {HEAD ~ the cover trim member} is engaged with {TAIL ~ the perimeter} of the concave surface to the housing, 
is engaged with
a cover trim member for engagement with the housing for enclosing the cavity when { HEAD ~ the cover trim member } is engaged with { TAIL ~ the perimeter } of the concave surface to the housing ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH