Keeps your letter/legal file boxes accessible during temporary storage or for short-term projects. Modular shell with steel support frame fits just about anywhere, stacks five units high to save floor space. Eliminates the need to stack or re-stack boxes. Durable shells with wire frames clip together vertically and horizontally for stability. Features Quick Set-Up assembly. File Box Accessory Type: Shell; For Use With: N/A; Inner Width: 13 in; Inner Height: 10 1/2 in.