The GS (Medium) cage is specifically designed to handle larger cassettes and triple cranksets
Model: RD-R3000-GS (Medium Cage)
Speeds: 9-Speed
Maximum Low Sprocket: 34T (minimum 28T)
Minimum Top Sprocket: 11T (maximum 14T)
Total Capacity: 43T
Max Front Difference: 20T
Cage Material: Steel
Weight: ~278g
Features: Wide link design, 2 fluorine-coated link bushings