The housing is provided with {HEAD ~ a slot} like {TAIL ~ longitudinal opening} , which on either side is flanked by a housing limb  
like
The housing is provided with { HEAD ~ a slot } like { TAIL ~ longitudinal opening } , which on either side is flanked by a housing limb
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH