Item Specifics: Model Name: Chain Roller. Item Type: Drive Belts. Color: White. Bearing Hole: 8mm. Notes: We provide clear pictures and measurements whenever possible. Please thoroughly check to ensure that this item matches your requirements. The actual items color may slightly differ from the listing image due to variations in computer screens. Your understanding is appreciated. The items size is measured manually, so please allow for a 0.5-1 inch difference (1 inch = 2.54 cm). There are no installation instructions included. Professional installation is highly recommended. Package Contents: 2x Chain Roller.