Shimano Sora CS-HG50 Cassette 12-25T

HG Sprocket Design Computer-designed HG (HyperGlide) sprockets insure fast and quiet down-shifts as well as instant up-shifts without hesitation.
Features:
High quality 8-speed Road cassette
Hyperglide sprockets have a computer designed tooth configuration with contoured shift gates, resulting in a crisp smooth shift even under load
Close ratio gearing allows a more efficient use of energy through finer cadence control
Sprockets are cut away to further reduce weight without reducing rigidity
Nickel-plated finish offers hard wearing resistance to corrosion
Corrosion-resistant steel cassette lockring
For Narrow 8-speed HG chains