Four Carbon Fibre carriers & 6 titanium sprockets make this Shimanos lightest 11-speed Dyna-Sys MTB cassette. Hyperglide sprockets have a computer designed tooth configuration with contoured shift gates, resulting in a crisp smooth shift even under load. 11-40T wide ratio gearing allows a more efficient use of energy through finer cadence control. Sprockets are cut away extensively & drilled to further reduce weight without reducing rigidity. Nickel-plated finish offers hard wearing resistance to corrosion Key Features Wide Range 11 Speed Cassette Rhythm Step Gear Progression HG-X11 Specific Tooth Profile Aluminium, Titanium & Steel Cogs