Pendaflex 82011 Poly Expanding File/Velcro Closure, 13-Pocket/Insertable Tabs, Letter, Black (82011) Textured-polypropylene 13-pocket file with 12 built-in tab dividers, A-Z and blank inserts, two interior window pockets with contents card, full-length label on spine and Velcro closure. Constructed of textured polypropylene20 times stronger than paper based material. 12 built-in tab dividers with A-Z and blank inserts add many organizational options. Two interior window pockets with contents card. Full-length label on spine.