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: 245mmI.D: 86mmMinimum Thickness: 2.5mmDisc Position: Front Left Fits: Yamaha WR250 Z 3RB 1991-1993 WR250 Z 4JW 1994-1997 WR250Z 1990 XT250 2009-2012 2014-2021 YZ125 1990-1991 YZ250 1990-1991