This accessory drive tensioner is designed and engineered by Litens - the world's largest supplier of original equipment (O.E.) belt tensioners in the world. The Litens replacement part meets all form, fit, and performance characteristics of the original equipment part (with the exception of not having the car manufacturer's logo or part number applied to the part). This part is manufactured to meet or exceed the performance and life specifications of the O.E. part. The part features a premium chrome-silicon steel spring, internal damping, a 6303 ball bearing and high strength steel pulley for long life and durability. Specifically designed for 08-10 Mack: 04 MR Series AMI Diesel, 05 MR Series AMI Diesel, 06 CV Series AMI Diesel, and 07 MR and LE Series AMI Diesel. 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.