Y_z_PW98_z_4_z_ FC_h_R81_z__z__h_P left hand crank arm unit, 172_dot_5 mm Shimano Ultegra Black One size 455_z_17_z_3_z_9343 Parts 455_z_17_z_3_z_9343 Transmissions Crank Arms one size SPRE FCR81_z__z__h_P LH crank arm unit 172_dot_5mm Y_z_PW98_z_4_z