Brembo 25539 Front Disc Brake Rotor Solid in construction, each rotor is vented to dissipate heat evenly and efficiently Machined and tested for a secure fitment Assembled and carefully tested to endure rigorous road conditions. Durable construction for repetitive usage and extended life The innovative Brembo-patented pillar venting technology increases overall rotor cooling and provides 40% more resistance to thermal cracking