Best Choice: High-strength steel plate plated with nickel-chrome, hollow design, light weight, a good balance between strength and weight, a cost-effective choice at a mid-range price, a very cost-effective mountain bike cassette flywheel. Design: High-precision HG internal thread ensures a firm connection with the bicycle hub. Smooth rotation and easy maintenance. Hollowing technology can easily reduce weight, making driving easier and quieter. Features: Special tooth shape and taper provide fast and accurate indexing conversion function, ensuring smooth and precise positioning of gears within the speed range. Complete models: Our mountain bike cassette speeds cover 8/9/10/11/12/13 speeds, and the gear ratio covers 11-30/32/34/36/40/42/46/50/52T, which can meet your different needs. Good compatibility: Our 8/9/10/11/12/13 speed mountain bike cassettes are compatible with Shimano and Sram drivetrains. Compatible with HG hubs (except Sram XD). Exquisite Gift: We provide you with bicycle rear hanger extender and mountain bike cassette installation tool in the package to help you install the cassette (Note: Under the gear ratio of 11-40T, the rear drivetrain hanger extender is not included) Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.