Shimano alivio hg400 9 speed mtb cassettepaired with the shimano hyperglide hg chains hg cassette sprockets deliver a fast and precise index shifting action the computer designed sprockets incorporate specifically positioned shift ramps and tooth profiles for improved chain control during shifting responsive smooth and low noise shifting is the result features 12 36t 12 14 16 18 21 24 28 32 36 11 32t 11 12 14 16 18 21 24 28 32 11 34t 11 13 15 17 20 23 26 30 34a 2 year warranty is offere