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