Paragon Performance Rotor Ring offers superior braking and cooling efficiency optimized for track and race applications. It features directional ventilation vanes to create suction, turbulence, and guides cool air through the rotor to achieve greater thermal capacity and increased resistance to cracking under harsh track condition. Made of CM-250 special formulated high carbon alloy cast iron, it allows for an optimal bite, thermal characteristics, high-temperature strength and durability. Rotor rings are heat treated to release stress in the rotor to avoid deformation and vibration then turned by state-of-the-art CBN surface machining to ensure better break-in with new brake pads. Vibration is reduced as the rotor lateral run-out is kept within 0.03mm and well-balanced: variations are kept within 2 grams. All rotor rings went through rigorous quality control procedures and inspections to ensure the rotor rings are fit for their purposes. The fully floating 2-piece design allows thermal expansion of the rotor while minimizing deformation and ensuring the rotor is self-centered with the pads. A slotted rotor improves braking consistency by maintaining a clean contact surface and dissipate heat generated and gases released when the pads come into contact with the rotors. Slotted rotors have a superior advantage over blank rotors in wet or raining conditions by preventing water films to form between the brake pad and rotor surface. Optimized the balance between mass and thermal capacity, our rotors improves overall handling by saving unsprung weight. Directional ventilation vanes for optimal thermal capacity and increased resistance to cracking. Increased cooling efficiency for extreme race conditions Fully-floating 2-piece design Minimizing brake fade & judder during extended sessions Rotor size: 378mm x 32mm Radial depth (D): 54mm Weighs 19.3 lbs (8.75 kg) Rotor to hat mounting system: T-Bobbbin (Long) - 12-bolt Fits: Ginetta G55 Standard / Super Cup / GT4 front *Replacement aluminum hats available Paragon part number: PRK.049.378.320.24500.03.01.F