Futures Son Of Cobra Twin Surfborad Fins - Grey/Marble The Son of Cobra Twin is designed with an extra cant angle to fit all Post-modern Twin fins with deep double concave bottom shape, especially the new …Lost Cobra Killer and other Son of Cobra Round Twin. These fins have a 7.5-degree cant angle (4 degrees is standard for twins) specifically to be paired with the Lost Surfboards x SOC “Cobra Killer” board model.  Solid Fiberglass construction combined with balanced base and height measurements provides maximum drive, while the thinner tip offers release and spring off the top. Template Category | Neutral (balanced, all-around) Construction | Fiberglass Size | Large Twin Center Fin Area 21.75 Height 5.68 Base 5.21 Foil FLAT