{HEAD ~ The first sidewall} and the protective wall cooperate to define {TAIL ~ a clevis structure} including a channel 
{ HEAD ~ The first sidewall } and the protective wall cooperate to define { TAIL ~ a clevis structure } including a channel
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH