ENDURO CZ6903VV Ceramic ZERO Rubber Sealed Deep Groove Bearing 17x30x7mm

Enduro ZERO Ceramic Grade Sealed Deep Groove Ball Bearings: These bearings are manufactured with silicone 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 wheels and cranks.
These bearings feature oversized grade 3 balls which roll on races which are ground to a mirror finish after receiving Magnetite and then Cryogenic treatments for hardness and longevity.
Benefits: Prevents moisture and dirt getting into the bearing, lubricated for life, more durable and with even lower rolling resistance than any 2RS bearing.
Note: If your bearing has the code 6903/61903 on the races and/or seals but has an 18mm bore, then you may need a [MR183072RS]