Brembo 25542 Rear Disc Brake Rotor Solid in construction, each rotor is vented to dissipate heat evenly and efficiently Machined with precision to provide optimum brake performance Assembled and carefully tested to endure rigorous road conditions. An electronic balancing system is used during the production process to eliminate an unbalanced weight distribution, thus eliminating the risk of vibrations The innovative Brembo-patented pillar venting technology increases overall rotor cooling and provides 40% more resistance to thermal cracking