Dyna-Sys specific (HG-X) 10-speed mountain drivetrain compatibility HollowTech-II (HT2): integrated drive-side spindle with external, wide-stance bottom bracket bearings for optimized rigidity and weight reduction Includes HT2 bottom bracket for 68/73mm shells (BB92 and BB30 adapter bearings available separately) Black double-anodized alloy outer and silver alloy plated inner chainrings for increased durability and Hyperdrive pin/ramp design for shifting performance (sizing optimized for Dyna-Sys gear ratios with matching 10sp cassettes) Hollow-forged Duraluminum crankarm/spider with a 4-arm, 64/104mm BCD chainring interface designed for 48.8mm chainline Color refers to crankarm and spider. 820g with rings and BB @ 175mm