dual use plastic packages for prepackaged retail product are constructed to be recyclable , making the package environment friendly . the package also provides an in - the - package display of the packaged product , and allows for inclusion of advertising and promotional material . the basic package structure is formed of injection molded virgin clarified polypropylene material , a transparent material . in one embodiment a sheet of advertising material is held in a thin narrow sleeve formed on the outside surface of the package , allowing the paper sheet to be withdrawn during recycling operations . in another embodiment , the printed material is printed on the thin plastic sheet , which is clearly recyclable , although recovering a darkened plastic when recycled . a novel lock device is disclosed . either or both those packages or any other retail packages may include the lock device to prevent the package from being opened in store . in this , the lock device includes a lock bar .