choice: high-strength steel plate with nickel chrome coating, hollow design, light weight, which provides a good balance between strength and weight, high cost effective choice in the middle price segment and very cost-effective Effective MTB cassette. Design:High-precision HG female thread ensures a firm connection to the bicycle hub. Smooth rotation and easy maintenance. The hollow-out technology can easily reduce the weight and make driving easier and quiet.Features: Special tooth profile and taper provide fast and accurate indexing conversion function to ensure smooth and precise positioning of gears in the speed range.Complete range of models: Our mountain bike cassette speeds cover 8/9/10/11/12/13 speeds, gear ratios cover 11-30/32/34/36/40/42/46/50/52T, to meet your diverse needs.Good Compatibility:Our 8/9/10/11/12/13-speed mountain bike cassette compatible with and Sram transmission system. Compatible with HG hubs (except Sram XD).Exquisite Gifts: We provide you with a bicycle rear hook extension and a mountain bike cassette installation tool in the package to help you install the cassette (Note: Under a gear ratio of 11-40T, the rear drivetrain hook extension is not included)