FNSL6R billet Forged six - piston calipers with 13 - 14 rotors deliver the ultimate combination for braking power and style in this group of kits engineered for traditional OEM spindles on American trucks. Built exclusively for 17 and larger wheels, FNSL6 kits enhance tire and suspension upgrades on all types of custom show and high performance dual - purpose street and track machines. A full range of options for caliper finishes and rotor designs are guaranteed to catch the eye of the most discriminating enthusiast while providing optimized brake performance for every individual application.