Rubbermaid Stak-A-File Wall-Mounted File Sorter, 3-Pocket Letter, Black (47021ROS). This handy storage bin provides a quick and easy way to add extra storage in limited space. Provides a flexible solution. Bins nest to fit together compactly and still make files accessible. Vertical storage keeps files and documents visible while stored. Tiered pockets allow easy viewing of contents. Mounts easily to any vertical surface with included hardware. For nearly 80 years, Rubbermaid has represented innovative, high-quality products that help simplify life. Recognized as a “Brand of the Century” for its impact on the American way of life.