Equip your semi to be Ready for the Road Ahead , with the Dayco 74.02" x 1.1" Poly Rib Heavy Duty Serpentine Belt, a crucial belt to quietly generate stable electricity. Thanks to its partnership with multiple tight pulleys and the alternator, this replacement belt is able to convert the mechanical energy from the engine into electrical power for accessories. Crafted with state-of-the-art EDPM rubber materials to reduce how often a belt should be changed. FleetPride is your First Click in Heavy Duty .