Air filter element for HS2 carburettor.
Air filters should be replaced about once a year or more often with a regular driving of your Classic Mini or Moke car.  This is the same 37mm high air filter that fits single HS2 carburettor or HS2 twin SU carburettors. The Cooper filter cannister that requires 2 filters was not quite so deep and therefore required the filter to be 37mm high as opposed to an original single carburettor which was 40mm high.