Shark Fins: If you ding your brake rotor, you have no brakes, which is bad enough by itself, but if you're racing it means YOU LOSE! The SCOTTS Sharkfin is 3/8" thick billet 6061 aluminum. It was the first shark fin that incorporates the brake caliper carrier as an integral part of the function. This means the axle passes throught the shark fin making it virtually indestructable and your brake rotor protected from defeat. This design is 10 times stronger than the "Bolt-On" type fins and it's a beautiful piece of work.