This Shimano HG-400 computer designed Hyperglide (HG) sprocket incorporates a specifically positioned shift ramp and tooth profiles for improved chain control during shifting. Fast and responsive indexed shifting is the result.. Use: MTB/Trekking
. Fast, quiet and smooth shifts
. Teeth have holes for weight-savings
. Compatible with IG chains
. Group: Alivio/ 9-speed
. Teeth: 11-25
. Gearings: 11-12-13-15-17-19-21-23-25