• Allows you to trace perfect 120° lines for fletching tape on vanes (Spin Wings, XS Wings, Eli Vanes, Spider Vanes etc.) • Works on all world archery shafts (23/64" and smaller) • Mark arrows without nock of arrow in • Place the end of the shaft in the brass pin and secure arrow with the nylon fasteners • Draw lines on your shaft to mark each place a vane should be placed