12Speed: 11T-40T / 11T-42T / 11T-46T / 11T-50T / 11T-52T. Material: Steel (36T,40T, 42T) / Steel + Aluminum Alloy (46T, 50T, 52T). SUNSHINE Bicycle Cassette 8/9/10/11/12Speed Freewheel 32/36T/40T/42T/46T/50T/52T Sprocket HG Structure Flywheel for SHIMANO/SRAM.
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