Spire Strong box shape arm, gussets on pedal and axle box. 2pc design. Smooth and rounded ankle friendly spindle boss. RSD & LSD compatible. Tubular heat-treated 4130 crmo arms & crmo axle. Item Specifications: BB Included: No, Crank Spindle Diameter: 22mm, Crank Length (mm): 170mm, Interface: 22mm, Raw Product Weight Grams: 901g, Crank Arm Material: Cr-Mo, Pedal Spindle: 9/16'', Defined Color: Black, Type: BMX,