This pulley is supplied by Litens Automotive - inventor of the first automatic belt tensioner in 1979 and today the world's largest supplier of Original Equipment (O.E.) belt tensioning and routing products. This pulley is produced for serpentine belt routing applications and as the pulley component on automatic tensioner applications. This pulley conforms to original equipment material, tolerances, and specifications. The part meets all performance and durability requirements. Fits Heavy Duty truck applications including Kenworth. Peterbilt, Freightliner, and Western Star. Comes pre-assembled with a new installation bolt and washer. Litens is the world's largest supplier of original equipment (O.E.) power transmission products. At Litens, we design systems that are more efficient, resulting in tangible fuel economy/emissions benefits. Litens holds over 2000 patents and continues to respond to the ever-changing automotive industry by investing heavily in new technology, facilities, and people. 90% of our line is made of products coming from the OE manufacturer, which makes the Litens Tensioning Products portfolio the purest OE tensioning line in the North American aftermarket.