US Patent 7434689 Packing unit comprising interconnection means

A packaging unit comprising a container body with a closed lower end, an open upper end and side walls between them; and a cap for closing the open end of the container body, which is pivotably attached thereto; wherein a floor section of the container body adjacent to the lower end thereof is designed such that said floor section can be inserted, to a predetermined extent, into the open end of another packaging unit, and means are provided for optionally alternatively connecting the floor section of the container body to the cap of another packaging unit.