From Fox’s website:

"The Fox #2 is our most popular shaper.  It is in the Knochenauer style of shaper, differing from a pure Knochenauer in the presence of a straight segment near the tip."

This shaper measures 15.4mm at the tip, 8.6mm at its narrowest point (41.6mm from the tip), and 9.4mm at the tube end.