Gates Alternator Decoupler Pulleys provide vibration isolation within the Accessory Belt Drive System resulting in smoother engine performance and efficiency and increased belt and component life. Line consists of overrunning alternator decoupler pulleys and one way clutches.Exact OE replacementPatented design unmatched by any other supplierTorsion spring absorbs engine vibration for quieter, smoother rideChosen by OEM to reduce noise, vibration and harshnessNote: Vehicles designed to use ADPs should never use a solid or one-way clutch pulley. These parts are not interchangeable, and failure to install the correct replacement can cause damage to accessory drive components.Gates - Driven By Possibility.