Shimano acera hg41 8 speed mtb cassettehigh quality 8 speed cassette features hyperglide sprockets have a computer designed tooth configuration with contoured shift gates resulting in a crisp smooth shift even under load gearing gives a low 30t sprocket making it easier to climb even the steepest of hills sprockets are cut away to reduce weight without reducing rigidity nickel plated finish offers hard wearing resistance to corrosion corrosion resistant steel cassette lockring for 8 speed hg c