You are buying a used long side axle shaft assembly from the front steer axle, out of the Military GMC 6x6 G749, M135, M211. It is roughly 49.5 inches long, with the outer shaft around 12.25 inches long and the inner around 38.5 inches.  The assembly part numbers are 7411309, GM 2283032, and NSN 2530-00-741-1309.  Its has some wear, rust, grease and crud.  Sold "as is".  Shipping 50 pounds by UPS at buyers expense.