a nice feature for ships, but no less so for carburettor floats. It's annoying when the sunk float can't close the inlet valve of the float chamber and the fuel pump first floods the float chamber and then the engine compartment with petrol. Our floats for almost all SU and Zenith Stromberg carburettors are made of nitrile rubber. Thousands and thousands of tiny micropores ensure guaranteed buoyancy, always! Excellent and permanently ethanol-resistant and suitable for E10.