Model:SM-CRM85 Series:SHIMANO DEORE XT Speed:12-speed Superior chain retention Special MTB gear teeth profile improves chain engagement and retention DYNAMIC CHAIN ENGAGEMENT+ Rider tunable Exchangeable single/double chainring Direct Mount Crankset can be used as common component Gear combination: 28T, 30T, 32T, 34T, 36T Package Including: - 1pcs 28T/30T/32T/34T/36T Chainring（M6100/M7100/M8100/M9100 NEED CHOOSE） Note: 100% authentic, without the original box.