Equipped with PLUS (Parallel Link Undercarriage System) option, D155AX-8 can be used in high-impact, rocky ground and low-impact, abrasive, sandy worksites. PLUS uses oil-lubricated, rotating bushings that are free to rotate, and PLUS ES shoe widths are 24, 26, and 28 in. Along with EPA Tier 4 Final emissions-certified engine, features include auto blade pitch mode, SIGMADOZER and automatic transmission with lockup torque converter, and ripper control lever with auto-return function.