{HEAD ~ Each} of the lateral surfaces 10 is formed with {TAIL ~ a rectangular fixing recess} 12 reaching the top surface 11 and the bottom surface of the main body 1 
is formed with
{ HEAD ~ Each } of the lateral surfaces 10 is formed with { TAIL ~ a rectangular fixing recess } 12 reaching the top surface 11 and the bottom surface of the main body 1
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH