The AYP 139245 is a genuine flat idler tensioner pulley designed for a wide range of riding lawn mowers and lawn tractors from brands such as Craftsman, Husqvarna, and Poulan. This essential component maintains proper belt tension, ensuring the efficient and reliable operation of the mower's drive system or cutting deck. Constructed for durability, this pulley features an outer diameter of 123.8 mm, an inner diameter (bore) of 17.46 mm, and a width of 28.6 mm. It is a direct replacement for several OEM part numbers, including Husqvarna 532139245, and is crucial for optimal belt performance.