The Son of Cobra Twin is designed with 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.