The shimano cs hg50 10 speed cassette is a high quality dyna sys 10 speed cassette it features close ratio gearing which allows a more efficient use of energy through finer cadence control and sprockets are cut away and drilled to reduce weight without reducing rigidity a nickel plated finish offers hard wearing resistance to corrosion and comes with a corrosion resistant steel cassette lock ring designed for use with 10 speed hg x mtb chains