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