Abstract: A molded plastic container has first and second portions which are relatively movable between open and closed configurations; and the two portions have first edges which are juxtaposed when the portions are closed. A T-shaped rail is fixed to the first edge of one of the container portions, and the rail extends along said edge for a significant length--except for a location where it is interrupted by two adjacent gaps. A pair of posts are fixed to the first edge of the second container portion, and the posts are positioned so as to be insertable into the two rail gaps when the two container portions are in their closed configuration. The posts have a transverse configuration which matches the transverse configuration of the rail, so that the posts may be described as forming geometric extensions of the rail when the two container portions are closed. A slide has an interiorly facing opening which is sized for engaging the rail and for being captured thereby.