{HEAD ~ The frame base plate} and the two frame end plates together form {TAIL ~ a C shaped structure} 
{ HEAD ~ The frame base plate } and the two frame end plates together form { TAIL ~ a C shaped structure }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL