Maximum Strength—Built for heavy daily usage and maximum stackability Heavy-duty construction offers maximum stacking strength that’s built to handle the weight of heavy bound reports. Ideal for stacking without shelving. Maximum security closure. A minimum of 35% post-consumer content. Inside dimensions listed below (w x h x d). Box Type: N/A; Material(s): 2 Ply Bottom, 2 Ply Side, 3 Ply End; Strength: Maximum; File Size Format: Printout Binders.