? STABLE & WATERPROOF MATERIAL - Our accordion folder made from high quality polypropylene (PP) plastic material (nontoxic and nonradioactive), Not easy to break and deformation. It's very stable and 100% waterproof. ? SECURE FLAP & CORD CLOSURE - The filing box’s full-size flexible flap and cord closure provide added security. To access stored items, simply fold back the flap. When finished, return the flap up and over the top of the folder and secure it in place using the cord closure. ? EXPANDING FILE FOLDER - Expandable 12 individual pockets for reliable partitioning for letter size & A4 size paper. Each pocket offers a generous amount of space, expanding to 10 inches. It’s expandable bottom adds additional capacity.