This pulley is manufactured by one of the largest original equipment pulley suppliers to ensure proper fit and performance. This pulley is produced for 2010-2013 KW T660, T680, T700/Peterbilt 365, 367, 384, 386, 388, 579, 587 with Paccar MX Engine. It's a serpentine belt routing application and conforms to original equipment material, tolerances, and specifications. This replacement part is made to the O.E. specified design and meets all performance and durability requirements. Heavy duty thermoplastic construction included. This pulley comes with a dust shield, spacer and installation bolt. 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.