Track Rollers of Excavator and Bulldozer: Material:35SiMn,35SiMnMo Warranty:One year Abundant casting technology,high quality Undercarriage parts for crawler crane, excavator and bulldozer, including track chains, track shoes, swamp shoes, sprocket & segment, track roller, idler, carrier roller, bolt & nut, etc.Which can suitable for many modle, such as CAT, KOMATSU, KOBELCO, HITACHI, HYUNDAI, ...