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