The K1 Keel is the perfect fin-set for a retro-twinnie. The Honeycomb core with the classic bamboo inlay give the K1 a medium flex pattern and the old-school template delivers blistering down-the-line speed and plenty of hold for direction changes. Construction Honeycomb core with Bamboo inlay Fin Height: 5.07" Fin Base: 6.65"...