The TeraFlex JK performance rear big rotor kit is the perfect upgrade for JK Wrangler owners requiring increased braking performance with larger tires. This kit allows the factory brake caliper and brake pads to be retained, while increasing the rotor diameter to 13.5”. The increased clamping distance from the rotor center results in greater braking leverage to allow stopping distance to be decreased substantially (larger rotor diameter = greater stopping power). The simple bolt-on installation upgrade requires absolutely no brake line modification or brake bleeding, and can be installed with basic hand tools.