{TAIL ~ a clasp lower part} having a dish shaped cross section to provide {HEAD ~ a lower surface} and an open top side with upwardly facing edges 
{ TAIL ~ a clasp lower part } having a dish shaped cross section to provide { HEAD ~ a lower surface } and an open top side with upwardly facing edges
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH