Johnson Duramax OPAL Non-Metallic cutless bearings adapt equally well to strut and stern tube mounts and are often used efficiently as rudder stock and pintle bushings. Johnson Duramax OPAL Non-Metallic cutless bearings use a specially formulated oil and chemical resistant nitrile rubber that is bonded to the Non-Metallic shell. Johnson Duramax Marine is the world’s largest supplier of marine bearings and each is made in the USA. Order your OPAL Bearing today. The measurements for the OPAL cutlass bearing are Shaft Size: 4-1/8 inches Outside Diameter: 5-1/4 inches Length: 16-1/2 inches.