Aftermarket flat idler sheave pulley for John Deere AUC11241 used on X500, X520, X530, X540, X580, X590 and other tractors and zero turn mowers. Durable plastic construction with a sealed ball bearing insert. Please utilize your own resources to ensure AUC11241 is correct for your application. Measurements are provided below for additional reassurance. AUC11241 is the current replacement for prior John Deere part numbers AM136441 and AM138081. Although this idler is identical in construction to AUC11241 please keep in mind that earlier part numbers may have been steel construction. Deere no longer offers this idler in steel construction.