Complex sentence: The obverse of the Paralympic medals feature the Paralympic emblem and an inscription in braille, and contains differing numbers of metal balls--which allow the visually impaired to audibly distinguish between the different types of medals by shaking them.
Split into simpler sentences: The obverse of the medals feature the Paralympic emblem and an inscription in braille. Each medal also contains differing numbers of metal balls, which allow the visually impaired to audibly distinguish between the different types of medals by shaking them.