7.5" diameter standard material brake disc for Cooper S; suitable for road application. The Cooper S disc is 7.5" in diameter and .375" thick when new. As they wear thinner, they become more prone to overheating and then warping. Sold each.
See also GBD0101 for the same disc in a superior material that better resists warping. See C-21A1265 for hi-spec grooved rotors.