a securing plate having {HEAD ~ plurality} of {TAIL ~ notches}, mounted to said second free end of said second arm 
a securing plate having { HEAD ~ plurality } of { TAIL ~ notches } , mounted to said second free end of said second arm
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH