This is a new Currie Jeep JK Wrangler rear disc brake rotor for use with our full floating JK rearend units. These rotors are most commonly sold when a customer buys our 8 lug JK bolt-in rearend package, intending to use the factory brakes. These new rotors are mandatory as they are already bored to 4.250" to clear the floater hub and drilled to the 8 on 6 1/2" wheel bolt pattern. For a pair of rotors, 2 of this part number would need to be purchased.