Alluminium Girling master cylinder reservoir cap.
Suits many English built cars from the early 1960s with disc brakes, hence the larger reservoir capacity.
This is an exact replica of the original and is therefore very useful with restorations and replacements.
Outside Diameter is 71mm (2.780 inches)
Ford Zephyr MK3 1962 to 1966
Ford Fairlane ZA 1967 to 1968