As the major supplier to heavy duty original equipment manufacturers, this Dayco No Slack Heavy Duty Tensioner is guaranteed to be engineered and manufactured to the strictest design specifications. The heavy-duty cast aluminum body and pulley arms translate into extra strength and durability. This Dayco Heavy Duty Tensioner features a patented flat spring design that’s engineered to handle the higher torque and power pulses exerted by today’s diesel engines. Rugged pulleys with double lifetime lubricated bearings deliver long lasting, dependable service. In addition, this Dayco Heavy Duty Tensioner features an extremely damped design using a wave spring and a metal ring with a bonded rubber surface to act as a radial shock absorber for the tensioner arm.