600-181-6820 Outer Diameter 221.2 mm (8.71 inch) Inner Diameter 135.9 mm (5.35 inch) Length 442 mm (17.40 inch) Overall Length 454.5 mm (17.89 inch) Bolt Hole Diameter 22.73 mm (0.89 inch) 600-181-6830 Outer Diameter 133.3 mm (5.25 inch) Inner Diameter 104.8 mm (4.13 inch) Length 402.1 mm (15.83 inch) Efficiency 99.9 Efficiency Test Std ISO 5011 Type Primary Style Round Media Type Cellulose