The "1967-77, 85-91 Fender Antenna Base Gasket 1-1/2" OD 1-1/16" ID" refers to a specific gasket used in vehicles produced between 1967 and 1977, as well as from 1985 to 1991, for the antenna base located on the fender. Here's what each part of the term signifies:

1. 1967-77, 85-91: This indicates the years of production for vehicles that would use this particular antenna base gasket. It covers a range of model years from 1967 to 1977 and then from 1985 to 1991.

2. Fender Antenna Base: This specifies the location where the gasket is used, which is on the fender-mounted antenna base. The antenna base is the part of the vehicle where the antenna mast is mounted and connected to the radio system.

3. Gasket: A gasket is a mechanical seal that fills the space between two mating surfaces, in this case, between the antenna base and the vehicle's body (the fender). It prevents water, dirt, and other debris from entering the vehicle through the antenna mount hole.

4. 1-1/2" OD, 1-1/16" ID: These measurements describe the outer diameter (OD) and inner diameter (ID) of the gasket, respectively. The outer diameter is 1-1/2 inches, while the inner diameter is 1-1/16 inches. This sizing ensures a proper fit between the antenna base and the fender, providing a tight seal and preventing any potential leaks.

Overall, the antenna base gasket serves an important role in maintaining the integrity of the vehicle's exterior and preventing damage caused by water infiltration. It helps to ensure that the antenna mount area remains dry and protected, prolonging the life of the antenna system and preventing corrosion or rust on the vehicle's body.