SRAM XX1 Chainset MTB QF-168, 32T black Large upper pulley offset automatically adjusts chain gap Straight parallelogram design with horizontal movement reduces shift force and improves drivetrain performance 12T X SYNC pulley wheels use silent tooth design TYPE 2 technologies Roller Bearing Clutch and Cage Lock 220g estimated weight Must be used in conjunction with SRAMs XX1 complete group rear derailleur cassette shifter chain cranks chainrings