600-181-6540 Outer Diameter 187 mm (7.36 inch) Inner Diameter 121.41 mm (4.78 inch) Length 381 mm (15.00 inch) Overall Length 393.7 mm (15.50 inch) Bolt Hole Diameter 17 mm (0.67 inch) 600-181-6560 Outer Diameter 116.4 mm (4.58 inch) Inner Diameter 88.3 mm (3.48 inch) Length 330.2 mm (13.00 inch) Efficiency 99.9 Efficiency Test Std ISO 5011 Type Primary Style Round Media Type Cellulose