Multiple carburettors need to draw in an equal amount of air to work efficiently. Listening to the sound of suction through a length of hose is time consuming and, depending on the ear, not necessarily that accurate. Carbalancer is accurate with its graded readout providing an instant comparison between carburettors. Works with Weber, Dellorto, SU, Amal and many others. Gunson G4053 - Carbalancer Internal combustion engines use a mixture of air and petrol to generate their power. The performance therefore is influenced by the air flowing into it and the petrol that is metered out by the carburettor. Unless the air flow in Twin or Multiple carburettors is correctly set, the correct mixture adjustment is unlikely to be achieved. Suitable for use on SU, Solex, Auto-Lite (Formoco) Stromberg, Weber and Zenith and can be adjusted to fit most carburettors including side-draught, down-draught with air intakes (Venurei) from 25mm to 67mm (1”-2”) diameter - Easy read scale indicates the air flow and allows - Provides smoother and better acceleration - Carbalancer can be adjusted to fit most carburettor - Easy to follow instructions