MTX solid discs are constructed using one complete segment of Japanese SUS 420 stainless steel then heat-treated to HRC 36+-2. Lightening and drill hole patterns are as per OEM designs to improve braking performance and reduce the temperature of the disc.MTX Discs provide amazing braking control for your motorcycle. All MTX discs are designed and manufactured with world-leading cutting edge technologies:Precision CNC machined and laser-cut technologyJapanese SUS 420 Stainless SteelReplacement for Original EquipmentOEM Design; lightening & drill hole patternsSpecifications:O.D: 220mmI.D: 121mmMinimum Thickness: 4mmDisc Position: Rear Fits: Honda CR125R 1989-1997 CR250R 1989-1996 CR500R 1989-2001