Product Description: Replacement (Pack of 2) Flat Idler Pulley for TimeCutter SS 4225 74721 Lawn Mower Specifications – Inside Diameter: 3/8 in. Outside Diameter: 4 1/8 in. Height: 1 1/2 in. See images 2 and 3 for more information. Includes – (2) Flat Idler Pulleys; ships as shown in first image. Be sure to check the part number or model to ensure this is the correct flat idler pulley for your unit. Also note that this may replace multiple part numbers.