The Murray 690439MA Lawn Tractor Stack Pulley Assembly 38-42" R is engineered to guide and transfer rotational force from the engine to connected components, helping blades and related mechanisms function as intended. By promoting smooth belt movement and reducing unnecessary wear, it contributes to consistent operation and proper equipment performance. This replacement part can help ... https://www.wholetoolbox.com/murray-690439ma-lawn-tractor-stack-pulley-assembly-38-42-r