The caster is rated as light duty because of light duty style of steel bracket. However with Steel core PU wheel, the caster can roll quietly and easily thanks to double ball bearings.
Despite the size of the caster (Ø100 - 200mm), R Series is rated as Light duty type - only 60 - 75 kgs per caster. Rubber tread is just light cushion but will help reduce noise and surface protection.