Enduro Extended Inner Race Rubber Sealed Deep Groove Ball Bearings: These types are manufactured with an extended inner race rubber seals inserted into the outer raceway and in contact with the inner race providing protection against the ingress of moisture, dust and other foreign matter and serve to retain the pre-filled grease in the bearing. Typically found in cycle suspension components and pivot points the extended inner serves to keep clearance between the frame parts and the bearing rather than using a separate spacer.
Seals: Seals can be easily removed for applications that only require 1 seal. Benefits: Prevents moisture and dirt getting into the bearing, lubricated for life, maximum load capacity
Note: These bearings may feature 'C3' on the box, this is not in reference to internal clearance and is a manufacturer code.