High Quality Polypropylene (Pp) Material (Nontoxic And Nonradioactive) Which Is Light And Tough, Waterproof And Durable With The Capability Of Protecting Documents In A Long Run. Expanding File Folder organizer can stand stable on any desktop. It can provide you more storage space when it expands and stand on table. keep your desktop cleanly and tidy. Moreover, the portable design of both sides of File Folder makes it easy for us to move it any time.