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. The flexible closed sides and polylaminated edges provide added protection for your contents. Each set includes Pressboard reinforcing-bottom inserts, tabs, and printer-ready, blank white inserts, making them ideal for organization. The 2-tone stock adds a professional touch to your filing system.