Extra durable unbreakable plastic construction holds up in busy environments. Easily mounts to wall (two screws and mounting tape included). Expandable system. Manufacturer"s 100% unbreakable guarantee. Three-Pocket Set (DEF-63601RT/DEF-63602RT). Expand with Single Pocket, sold separately. Hanging File Systems Type: Expandable Multiple Pockets; For File Size: Letter; Overall Height: 6 1/2.