Pendaflex 13-Pocket Expanding Spiral File, Letter Size, Foam Poly, Smoke, 1/Each (1121) Moisture-resistant foam polypropylene expanding file with multiple pockets, easy-access spiral flap, 4" capacity and elastic cord closure. Lightweight, flexible and textured poly is 20 times stronger than paper based material and moisture-resistant to protect your documents. Features a spiral flap that stays out of the way for easy access. Unique expanding bottom slides out to 4" wide for more holding capacity. Secure elastic cord closure.