Keeps your letter/legal file boxes accessible during temporary storage. Flip the lid and place the box inside for frequent, easy access to your files. Modular shell with steel support—stacks five units high to save floor space and eliminates the need to stack or re-stack individual boxes. Durable construction with wire frames that clip together vertically and horizontally to ensure stability. Features Quick Set-Up assembly. File Box Accessory Type: Shell; For Use With: Letter/Legal-Sized Lift-Off Lid Filing Boxes; Inner Width: 12"; Inner Height: 15".