Model CSMX3 is much lighter than CSMS3.

Model No.: CSMS3 / CSMX3 (according to your option)

Speeds: 10-Speed (Wide Ratio)

Number of Teeth: 11-40T / 11-42T / 11-46T (according to your option)

11-40T: 11-13-15-18-21-24-28-32-36-40T

11-42T: 11-13-15-18-21-24-28-32-36-42T

11-46T: 11-13-15-18-21-24-28-34-40-46T

11-51T: 11-13-15-18-23-28-33-39-45-51T

Chain Compatibility: 10 Speed