 at least certain of said adapter blocks have a length dimension equal to the distance between hub axes of two connector elements when joined by {HEAD ~ a rod element} having {TAIL ~ a length Lx}, where “x” is a whole number from 1 to n 
having
at least certain of said adapter blocks have a length dimension equal to the distance between hub axes of two connector elements when joined by { HEAD ~ a rod element } having { TAIL ~ a length Lx } , where “ x ” is a whole number from 1 to n
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH