Pendaflex SureHook Reinforced Extra Capacity Hanging Box Files feature SureHook Technology with built-in tension springs, ensuring folders stay on track and slide with ease. These legal-size folders have flexible closed sides and polylaminated tops to safeguard contents. Each file includes Pressboard reinforcing-bottom inserts, tabs, and printer-ready, blank white inserts. With a 3" expansion and made from 10% total recycled and 10% post-consumer fiber, these files are also SFI Certified.