Retention channel 915 extends substantially {TAIL ~ the entire length} along {HEAD ~ each edge} of each part receiving area 910 
Retention channel 915 extends substantially { TAIL ~ the entire length } along { HEAD ~ each edge } of each part receiving area 910
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH