This track roller is a single row, self-retaining ball bearing design with a particularly thick-walled outer ring, a ball and cage assembly, and an inner ring. Bore diameter is 4.0 mm, outside diameter 13.0 mm, height 4.0 mm, and net mass is 2.78 g. Axial guidance of the outer ring is provided directly by the balls, and lip seals are fitted on both sides (2RSR), combining axial and radial sealing action. The thick-walled outer ring allows the track roller to run directly on a mating track surface, with the balls handling axial guidance instead of a separate guiding shoulder. The double-sided lip seal keeps contaminants out of the ball and cage assembly and retains internal lubricant, making the bearing suited for continuous rolling contact applications where the outer ring itself acts as the running surface.