Drilled Nitrac discs offer improved cooling and water removal and are lighter than grooved equivalent. Not recommended for track use as drilled discs are more prone to cracking under stress. Drilled discs are an excellent choice for road use for the more spirited driver. We recommend upgrading to – NITRAC MAX DCT -- Deep Cryogenic Treatment to enhance longevity and performance. Also available with an optional Black Phosphate Finish (BPF) coating to help with corrosion prevention.