Precision tooth profiling ensures accurate shifting even under load. Heat treated steel cogs for maximum durability. Alloy carrier and machined holes on the three largest cogs offer additional weight savings. Alloy lockring included. Compatible with SRAMShimano 8910 freehub bodies NOT compatible with Shimano 10-only freehub bodies. Compatible with SRAM or Shimano 10-speed chains. 230g weighed with lockring.