Wilwood's GT 36 Curved Vane Spec-37 rotors are crafted from a unique iron alloy, engineered to endure extreme temperatures and resist distortion, warping, cracking, and wear. This alloy is derived from technology and materials used in Wilwood's extreme duty military spec rotors. Paired with the GT Series' asymmetrical face slot pattern and individual dynamic balancing, these rotors ensure the smoothest braking performance.