Challenger agriculture equipment includes the world's two most powerful production tractors --- the MT975B 4WD articulated tractor and the MT875B rubber-tracked tractor --- both with 570 horsepower. In addition to four models of 4WD articulated tractors and eight rubber-tracked tractor models, Challenger dealers also offer a full line of wheel tractors from compact tractors to more-than-250-horsepower rowcrop tractors, tractor loaders, Class VI, VII and VIII combines, and a full line of hay tools. Since 1987, when the first Challenger brand rubber-tracked tractor was introduced, the Challenger name has stood for professional-grade ag equipment, and for exceptional, high-quality, in-field service and parts support.