8 ball bearings suitable for the wheels of the Polaris 280 or 180 robot. Corresponds to the reference C60 C-60. Dimensions: external 28.4 mm, internal 15.4 mm. Plastic bearing body and stainless steel balls, identical to the original, for optimal operation and greater longevity. Replacing the bearings on your Polaris robot is very simple and quick to do yourself.