The various wires connecting the wings and struts together are collectively known as "flying wires". These are long and slender with a round cross section, and threaded on the ends. By turning the entire wire you can adjust their length. I needed a device that would allow me to get a good grip on them, but without leaving any scars or tooling marks (i.e. no Vice Grips here!). I decided to make some "vee blocks" for this