10s cassettes to 8s / 9s freehub, or, 8s / 9s / 10s cassette to 11s freehub. - Put 8/9/10s cassette sprocket on 11s freehub, needs 1pc 1.85mm spacer. - Put 10s cassette sprocket on 8/9s freehub, needs 1pc 1mm spacer.
IceToolz Bottom Bracket Bicycle Cassette Chain Lockring Tools for Shimano/Sram
2.5mm Cassette Freehub spacer, for Shimano SRAM
2.0mm Cassette Freehub spacer, for Shimano SRAM, 8/9/10 speed on 11 speed hub
3.0mm Cassette Freehub spacer, for Shimano SRAM
1.5mm Cassette Freehub spacer, for Shimano SRAM
