Plastic covering cap

A plastic covering cap adapted for mounting in fuel tank inlets of varying internal dimension including a base member comprising a flange defining an aperture in the central portion thereof, a flexible sleeve member of a given thickness extending downwardly from said flange, said sleeve adapted to be inserted into the interior of a filler spout, said sleeve including one or more radially outwardly extending flexible annular rings, each having a radial dimension substantially greater than said thickness of said sleeve member at least one of said rings being resiliently deformable to engage said filler spout to secure said cap in place while at least one of said rings being flexibly engageable with a side wall of said filler spout to seal against the flow of liquid therebetween, a cover member integrally hingedly attached to said base member comprising a lid adapted to overlie said base member when in a closed position, a plug extending downwardly from said lid and adapted for insertion into said aperture defined in said flange of said base member to seal said aperture, and a flexible plastic strip integrally formed with and extending between said base and said cover to hingedly secured said base and said cover together.