Kit contains inner and outer bearings (both sealed), inner and outer felt seal:
HS004: Outer seal
HS003; Inner Seal
BB625S; Inner Bearing
BB634S; Outer Bearing
Rubber Sealed Deep Groove Ball Bearings: One of the most commonly used 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.
Seals can be easily removed for applications that only require 1 seal.
Benefits: Prevents moisture and dirt getting into the bearing, lubricated for life, cost effective solution