Polished Finned Aluminium Air Cleaner OTAC4FCPolished Finned Aluminium Air Cleaner4" O. D X 3 5 8" H Suit 2 5 8" Carburettor Neck OTAC4FC AC4FC This O'Brien Truckers original has deep traditional fins that allow you to paint it to match your engine colour and add an extra zing to your engine compartment. They come with a subtle grey coloured lifetime cotton gauze washable element contained in a never rust wire mesh. No cheap paper element here!