This 40 mm venturi diffuser is specifically designed for the Weber 46IDA3C carburettor, equipment commonly found on classic vehicles equipped with high-performance fuel systems. As part of a restoration or careful maintenance programme, replacing the venturi diffuser is an essential step to restore proper carburettor function and ensure optimal fuel supply. This new part guarantees a restoration faithful to the original configuration of the Weber 46IDA3C carburettor.