Timmy Fin Placement ToolWe collaborated with San Clementes shaper and craftsman extraordinaire Timmy Patterson to bring the easiest and most accurate tool for setting the fin placement to the masses. The Timmy Fin Placement Tool is designed to place markings on your shaped blank for thrusters, quads, 5 fins and twins. 3. 5" for center fin 11" for side fins 5. 5" for quad rears 9. 5" for twins Used to mark the fins on boards of some of the worlds best surfers, you can trust