Specifications Hign-concerned Chemical:None Type:MTB Bike Freewheel is_customized:No Model Number:M6100/M7100/M8100 Sensitivity:108 Sounds Flywheel Adjustable Gear Number:12 Material:Alloy Gear Teeth:10-51T Freewheel Speed:12 Origin:Jp(origin) Components:Freewheel Cassette Sprocket 12-speed CS-M6100-12 - 12-Speed - HYPERGLIDE+ - MTB Cassette Sprocket With its BEAM SPIDER construction, the new M6100 12-speed cassette shaves weight while increasing SHIMANO's MTB gearing range another gear. Using SHIMANO's new MICRO SPLINE freehub body and HYPERGLIDE+ tooth profile, the 10-51T cassette delivers advanced shifting performance. Trickle down technologies at its best HYPERGLIDE+ provides fast and smooth shifting BEAM SPIDER construction cuts weights and boosts stiffness 10-51T wide range 12-speed gear combination CS-M7100-12 SLX - 12-Speed - HYPERGLIDE+ - MTB Cassette Sprocket With its BEAM SPIDER construction, the SLX M7100 12-speed cassette shaves weight while increasing SHIMANO's MTB gearing range another gear. Using SHIMANO's new MICRO SPLINE freehub body and HYPERGLIDE+ tooth profile, these 10-45 and 10-51T cassettes deliver advanced shifting performance. Advanced shifting performance provides the confidence to enjoy any trail Pedal continuously while shifting HYPERGLIDE+ Lighter and stiffer cassette sprocket construction reduces inertia and increases acceleration BEAM SPIDER Lighter drivetrain set up 10T lowest sprocket realized by new FREEHUB body construction MICRO SPLINE Wide range and close step 12-speed drivetrain CS-M8100-12 XT - 12-Speed - HYPERGLIDE+ - MTB Cassette Sprocket With its BEAM SPIDER construction, the new XT M8100 12-speed cassette shaves weight while increasing SHIMANO's MTB gearing range another gear. Using SHIMANO's new MICRO SPLINE freehub body and HYPERGLIDE+ tooth profile, these 10-45 and 10-51T cassettes deliver advanced shifting performance. Definitive shifting performance New shift ramp designs provide the fastest, smoothest shifts by HYPERGLIDE+ BEAM SPIDER Lighter and stiffer construction Reduces cassette inertia resulting in faster acceleration and increased chain security MICRO SPLINE 10T lowest sprocket realized by new FREEHUB body construction Wide range and close step 12-speed drivetrain