Tuff Pockets are virtually indestructible yet they look like standard redrope files. They pass the toughest tests and last for years, even when loaded with large, heavy files, catalogs or notebooks. 6-1/2" high sides and bottoms are fully lined with tear-resistant Tyvek. The tops feature special rollover reinforcement at the top. Heavyweight, 7/8" front and back panels provide rigid support and have a hidden reinforcement strip at the point of greatest stress.