Pins associated with the housing seat through selected apertures in {TAIL ~ the bar} at {HEAD ~ a determined position} 
Pins associated with the housing seat through selected apertures in { TAIL ~ the bar } at { HEAD ~ a determined position }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD