Y73T22230 - Shimano SG-3R40 Nexus sprocket for 1/3/4/7/8-speed Alfine and Nexus systems, 22T steel, black. - 4524667208129

Y73T22030 - Shimano SG-3R40 Nexus sprocket for 1/3/4/7/8-speed Alfine/Nexus hubs, 20T steel construction in black. - 4524667208105

Y73T21830 - Shimano SG-3R40 Nexus sprocket, compatible with 1/3/4/7/8-speed Alfine and Nexus systems. 18T steel sprocket in black. - 4524667208082