Esselte Pendaflex SureHook Blue Hanging File Folder features built-in tension springs to ensure that rods are strong, sturdy and will bend less. Letter size file folder with 1/5 cut tabs and inserts has reinforced poly-laminated top and bottoms. Acid free and PVC free folder stays on the rails, slides with ease and will not buckles under pressure. Durable file folder containing 10% post-consumer fiber is 20 per Pack.