Notes: 100277-13N STUD R18x2.5 - D18x1.5 - L72.5 - 10.9 is original BOBCAT-SAMBRON product. 100277-13N STUD R18x2.5 - D18x1.5 - L72.5 - 10.91 is commonly used in transmissions/axles/engines . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849