Notes: 81520.9 DOUBLE U-JOINT B310 55 ° DF L=615 (165 Z is original DOOSAN product. 81520.9 DOUBLE U-JOINT B310 55 ° DF L=615 (165 Z1 is commonly used in transmissions/axles/engines . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849