Truvativ X-9 Chainset GXP 2x10sp 175mm Grey 39-26tHollow Forged AL crank arms for lightweight super stiff durabilityX-Glide 2X10, 26-39, gearing Bottom bracket not includedArm Material AL-7075 Weight 881 Grams (GXP w/BB) Gear Ratios 26-39,Bolts AL Double Hex Type Recommended Chain 10 Speed Material Crank Arm Material Hollow forged, Chainring Inner Position - Material 7075