Shimano XT M771 10 Speed 11T Cog With all these drivetrain modifications flying around, maybe you need a lower low out back. Or maybe you are just in need of the additional speed. Either way, the Shimano XT M771 10 Speed 11T Cog will give you that taller end on your 10-speed rig. Shimano XT M771 10 Speed 11T Cog Specifications: Material: Steel Genuine Shimano componentry Compatibility: 10-speed Teeth: 11T