Fuel Suction Inlet Member

A sender gauge adaptor includes an adaptor body pressed against a bottom wall of a fuel tank by a spring. The adaptor body includes a suction inlet part having a hollow cylindrical shape that opens downward. Recesses allowing fluid communication between the interior and the exterior of the suction inlet part and projection parts having a polygonal-shaped lower surfaces are alternately arranged in the circumferential direction along a lower end of the suction opening. The adaptor body includes a seat part in surface contact with the bottom wall of the fuel tank at a position below the lower surfaces of the projection parts.