52 of the spout base 18 is dimensioned to fit through a central aperture 53 in the retainer 20 an intermediate portion 54 of the spout base 18 has an outside diameter slightly less than the inside diameter of the neck 16 so that in the storage mode of fig5 a major portion of the spout base 18 is receivable within the neck and is centered therewith the seal cap 19 is an imperforate circular element having a bowl shaped configuration including a peripheral flange 57 as indicated in fig7 this peripheral flange 57 includes an integral lip seal 58 the seal 58 has a thickness substantially less than that of the cap flange 57 and is adapted to be resiliently axially deflected from the unstressed conical configuration of fig7 to the relatively flat shape assumed in the storage mode of fig5 the outside diameter of a main dish portion of the seal cap is slightly smaller than the retainer aperture 53 thereby enabling this portion to nest in the aperture and be centered by it over the spout base 18 the main body of the retainer 20 is generally cup shaped and is defined by a generally radial end face 61 surrounding its aperture 53 and a cylindrical skirt 62 depending from the periphery of the end face and sized to extend over the neck 16 a plurality of lugs 63 extending radially inwardly from the interior wall of the retainer skirt 62 engage as female threads with the neck threads 29 two sets of diametrically opposite finger grips 67 equally spaced about the outer circumference of the retainer skirt 62 extend outwardly from the skirt in generally radial planes lower.