The CF-Twin was designed in house by the Captain Fin Crew. It gives you the feeling of a twin fin with the added stability of a thruster. Front Height: 5.15 / Base: 4.8 / Area: 18.95 / Rear Height: 3 / Base: 2.8 / Area: 6.7. Fiberglass Multi-Color Layup / Compatible with Futures Fin boxes.