An “AF Expander -6 to -8 silver ” is a hose fitting used in high-performance automotive applications, especially for fuel, oil, and coolant systems. The specification describes the following attributes:
AF: A brand name, most likely Aeroflow, which manufactures premium silicone and aluminum fittings.
Expander: Refers to the function of the fitting, which increases the hose diameter from a smaller size to a larger one. It is also known as a reducer or adapter.
-6 to -8: Specifies the size of the fitting in AN (Army-Navy) sizing standards, which are based on 1/16-inch increments.