Budget MR121 Rubber Sealed Headset Ball Bearing 45x45 deg with Internal and External Chamfer 30.9x41.8x8mm - Allow 2-3 Days

Rubber Sealed Angular Contact Headset Ball Bearings: These types are manufactured with 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.

These particular bearings are suited to headset applications

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