SHIMANO Nexus SG-3C40 Hub 3-Speed Cog Sprocket Wheel 23T Silver – Y33060200
Shimano Nexus and Alfine cogs will work with either 1/8″ or 3/32″ chains
Cog Snap Ring: Used to attach driver cog to internally geared Shimano Nexus and Alfine hubs
Original Shimano parts guarantee that all components work perfectly for optimum performance and maximum safety and longevity.