This axle seal is used in all of our RockJock 44 & 60 frontends with standard tubes and 30 spline inner axles. This seal is 2.625" o.d. on the machined area where is presses into the housing, and 2.370" o.d. on the body of the seal. If your tube i.d. is smaller than 2.370" - your frontend is most likely set up for the 60-8013 expandable seal! Sold each.