Toro 18.00 Inch OEM Extended Wiehle Roller Assembly. This roller has a 2.50 inch diameter. This Assembly comes with the roller tube, bearings, lock nuts, roller shaft & washers. A Wiehle roller has groves built into the roller as a standard Wiehle roller is smooth. Toro OEMs are created to keep your equipment up and running with the highest quality parts. To verify that this fits your Toro equipment, please do a model & serial number search.