As the name implies Sport Japan discs were originally designed for the Japanese market where tough looks and high performance are important factors. Sport Japan discs feature 6 grooves on the braking surface which deglaze the pads and help vent the gasses and scale which cause fading. Drilled holes remove heat from the discs, allowing the discs to run cooler. All Sport Japan discs are heat treated for strength, milled on numerically controlled machines and hand finished to ensure the smoothest possible braking surface. Sport Japan Discs are TÜV approved.